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Background: Autosomal recessive woolly hair/hypotrichosis (ARWH/H) is caused by mutations in LIPH. Homozygotes for the LIPH c.736T>A (p.C246S) mutation, the most prevalent genotype in Japanese patients, present varying degrees of hair loss; however, determinants of this phenotypic diversity remain elusive., Objectives: To establish methodologies for quantitative assessment of clinical severity and provide a detailed characterization to elucidate the factors contributing to phenotypic divergence., Methods: Digital image analyses were conducted to convert clinical severities into numerical values. Eight patients with ARWH/H were classified into three groups (mild, severe, very severe), based on severity scores. Dermoscopic images were collected and assessed for total hair numbers and hair thickness for intergroup comparisons., Results: The image analysis detected a difference in hair thickness but not in total hair numbers, between mild and severe cases. A marked decrease in total hair number was noted in an atypical very severe case. Histopathologically, a patient with a mild case demonstrated hair miniaturization and a high telogen/anagen ratio without a decrease in total hair count, endorsing dermoscopic observations. Two children demonstrated spontaneous improvement without an increase in total hair numbers, and two adults responded well to topical minoxidil with increased total hair numbers and hair thickness., Conclusions: The difference in the frequency of underdeveloped hairs may be a major factor contributing to the clinical diversity of hair sparseness in LIPH c.736T>A homozygotes with ARWH/H. Hence, pharmacological modification to thicken existing fine hairs may provide a therapeutic strategy., (© 2016 British Association of Dermatologists.)

Background: Androgenetic alopecia (AGA) is the most common type of baldness in men. The balding process is associated with the gradual miniaturization of hair follicles and successive hair loss. However, the relative contributions of hair density and diameter to AGA are still unclear., Objectives: Hair density and hair diameter were investigated in Japanese men with or without AGA to elucidate the importance of these factors in the balding process., Methods: Male Japanese subjects with or without AGA (n = 369) were included in this study. Hair appearance at the vertex was evaluated by comparison with a series of standard photographs. Hair density was measured using a phototrichogram-based videomicroscopy technique, and hair diameter was assessed by comparison with a series of calibrated threads on the phototrichogram image., Results: All subjects with AGA were ≥ 25 years of age. The mean percentage of thick hairs (> 80 μm) in all subjects with AGA was significantly lower than that in subjects without AGA aged ≥ 25 years (P < 0·01), but the mean percentage of vellus hairs (< 40 μm) in subjects with AGA was significantly higher (P < 0·001). By contrast, the mean density of the hair in all patients with AGA did not significantly differ from the density of those without AGA aged ≥ 25 years. However, the mean density of the hair in subjects without AGA aged < 25 years was significantly higher than that of both subjects without AGA aged ≥ 25 years (P < 0·001) and all subjects with AGA., Conclusions: Hair loss in men with AGA results mainly from the miniaturization of hair follicles rather than the loss of hair (shedding), at least for individuals who are ≥ 25 years of age and present with AGA., (© 2014 British Association of Dermatologists.)

Background: A patient's ethnicity can be an important clue in the diagnosis of scarring alopecia as some disorders such as traction alopecia (TA) and central centrifugal cicatricial alopecia (CCCA) are more prevalent in or exclusive to African-Americans., Objectives: To perform a retrospective review of 60 scalp biopsies from African-American patients including 25 cases of CCCA, 22 cases of TA, five cases of frontal fibrosing alopecia, three cases of discoid lupus erythematosus, three cases of hair breakage and two cases of alopecia areata., Methods: Serial horizontal and vertical sections were examined., Results: Features characteristic of the African-American scalp include: golf club-shaped bulb, elliptical shape of the hair shaft, asymmetrical outer root sheath and paired grouping of hair follicles. Clues to the diagnosis of CCCA include: premature desquamation of the inner root sheath, goggles and naked hair shafts in fibrous streamers. Diagnosis of TA is suggested by preserved sebaceous glands along with follicular miniaturization and drop-out., Conclusions: The clues reported here aim to help the dermatopathologists to: recognize at a glance that they are dealing with a scalp biopsy from an African-American patient; make the most probable diagnosis by connecting the clues (even if only vertical sections are present); and understand the morphological basis for the susceptibility of the African hair to damage., (© 2012 The Authors. BJD © 2012 British Association of Dermatologists.)

Background: Many of today's treatments associated with 'thinning hair', such as female pattern hair loss and telogen effluvium, are focused on two of the key aspects of the condition. Over-the-counter or prescription medications are often focused on improving scalp hair density while high-quality cosmetic products work to prevent further hair damage and minimize mid-fibre breakage. Fibre diameter is another key contributor to thinning hair, but it is less often the focus of medical or cosmetic treatments., Objectives: To examine the ability of a novel leave-on technology combination [caffeine, niacinamide, panthenol, dimethicone and an acrylate polymer (CNPDA)] to affect the diameter and behaviour of individual terminal scalp hair fibres as a new approach to counteract decreasing fibre diameters., Methods: Testing methodology included fibre diameter measures via laser scan micrometer, assessment of fibre mechanical and behavioural properties via tensile break stress and torsion pendulum testing, and mechanistic studies including cryoscanning electron microscopy and autoradiographic analysis., Results: CNPDA significantly increased the diameter of individual, existing terminal scalp hair fibres by 2-5 μm, which yields an increase in the cross-sectional area of approximately 10%. Beyond the diameter increase, the CNPDA-thickened fibres demonstrated the altered mechanical properties characteristic of thicker fibres: increased suppleness/pliability (decreased shear modulus) and better ability to withstand force without breaking (increased break stress)., Conclusions: Although cosmetic treatments will not reverse the condition, this new approach may help to mitigate the effects of thinning hair., (© 2011 Procter & Gamble. BJD © 2011 British Association of Dermatologists.)

Background: Androgenetic alopecia (pattern baldness) affects approximately half of all white-skinned men and women over the age of 40 years. Based on preclinical studies in mice in which topical fulvestrant (ICI182,780, an anti-oestrogen) caused telogen hair follicles to enter anagen, thereby causing hair growth, a topical formulation of fulvestrant was developed for the potential treatment of androgenetic alopecia., Objectives: To evaluate the efficacy of fulvestrant solution in stimulating hair growth in men and postmenopausal women with androgenetic alopecia in two randomized, phase II, minoxidil- and/or vehicle-controlled studies., Methods: One hundred and two white-skinned men aged 18-50 years with Norwood/Hamilton grades III, IIIv, IV, V or Va androgenetic alopecia received topical fulvestrant 70 mg mL(-1) solution, vehicle or minoxidil 2% solution twice daily for 16 weeks. Seventy postmenopausal women with Ludwig grade 1 or 2 androgenetic alopecia received topical fulvestrant 70 mg mL(-1) solution or vehicle twice daily for 16 weeks. The endpoints in both studies were hair density, cumulative hair thickness and hair growth rate, measured by TrichoScan analysis of digital images., Results: There were no statistically significant differences favouring fulvestrant over vehicle at study end (day 113) for any of the efficacy parameters in men or women. Statistically significant differences in favour of minoxidil over fulvestrant were seen from day 57 onwards for hair density, cumulative hair thickness and hair growth rate in men., Conclusions: These results indicate a lack of effect of topical fulvestrant in the treatment of subjects with androgenetic alopecia. The reasons for this lack of effect remain unclear.

Background: Although female pattern hair loss can be a feature of hyperandrogenism, many women with hair loss show no clinical or biochemical features of androgen excess. It is possible that hair loss in nonhyperandrogenic women is due to a high level of response to androgens by scalp hair follicles. In this study we explored this idea using sebum excretion as a marker of the cutaneous end-organ response to androgens., Objectives: To test the hypothesis that hair loss in nonhyperandrogenic women is due to an increased cutaneous end-organ response to androgens., Methods: We studied 100 women, 41 with female pattern hair loss (without hirsutism), 29 with hirsutism (with and without scalp hair loss) and 30 subjects without hair problems. We measured hair density on the frontal scalp, forehead sebum excretion, serum free androgen index (FAI), and body mass index (BMI)., Results: The mean FAI was significantly raised in hirsute women compared with nonhirsute women (P < 0.001), but there was no difference in FAI levels between nonhirsute women with and without hair loss. The mean BMI was also significantly elevated in hirsute women (P < 0.01) but there was no difference in BMI between nonhirsute women with and without hair loss. The mean sebum excretion was higher in hirsute women than nonhirsute women but the difference was not statistically significant. There was no difference in sebum excretion between nonhirsute women with and without hair loss. There was no correlation between hair density and sebum excretion., Conclusions: Our results show that sebum excretion is not elevated in women with female pattern hair loss. This may indicate that different androgen-response pathways operate in controlling hair growth and sebum excretion. The alternative explanation is that nonandrogenic mechanisms are involved in mediating hair loss in some women.

Background: Hair loss from cytotoxic drugs is classically ascribed to the loss of fractured hairs (anagen effluvium). Telogen hair loss has also been described but some authors have denied any effect on the hair cycle. There are conflicting reports on a protective effect of pretreatment with a vitamin D analogue on cytotoxic drug-induced hair loss in rodents., Objectives: To investigate the process of cytotoxic hair loss and any protective effect on the hair of pretreatment with topical calcipotriol., Methods: Breast cancer patients who were about to receive cycles of chemotherapy with cyclophosphamide 600 mg m(-2), methotrexate 40 mg m(-2) and 5-fluorouracil 600 mg m(-2) were recruited and randomized to receive calcipotriol scalp solution 50 microg mL(-1) or vehicle. The solution was applied twice daily from 4 days prior to chemotherapy and continued for 14 days in each treatment cycle. Shed, plucked and cut hairs were sampled. Absolute shed rates, the proportion of major hair types, the presence of proximal hair shaft changes, regrowth (using the new anagen hair count) and hair density were assessed., Results: Ten patients receiving calcipotriol and 14 receiving vehicle completed three treatment cycles and nine from both groups completed six cycles. There was no detectable effect of calcipotriol on the proportion of patients experiencing minimal hair loss from chemotherapy, shed rates, plucked telogen and fractured hair counts, the morphology of shed and plucked hair, hair regrowth or hair density. Combining results of the treatment groups, there was a large variation in the impact of chemotherapy on hair loss, from total loss in five patients to no obvious loss in five. Excluding the latter, during chemotherapy shed telogen hairs (mean 81% of shed hairs) predominated over fractured (12%) and anagen hairs (6%) (P = 0.0002). The major pathological change was proximal hair shaft tapering, baseline mean 3% of shed hairs rising to 48% (P = 0.0005) during treatment, and there was a consequent decrease in normal telogen hairs, baseline mean 98% of all telogen hairs falling to 55% (P = 0.0005) during treatment. The pathological tapered telogen hairs had normal or small, sometimes diminutive, bulbs. Fracturing of hairs with diminutive bulbs produced typical 'exclamation mark' hairs., Conclusions: The cardinal effects of cytotoxic drugs found in this study were tapering of the proximal hair shaft and premature entry of the follicle into telogen, conflicting with the conventional view that affected hair follicles continue in anagen. There was a resulting effluvium of a mixture of tapering telogen hairs and fractured hairs. As entry into telogen is an integral part of the process, cytotoxic hair loss may be regarded as a variant of the conventional 'telogen effluvium' and we propose the term 'atrophic telogen effluvium'. There was no obvious protective effect on the hair loss of prior treatment with topical calcipotriol.

Background: Recent studies of antidandruff shampoos or tonics containing antifungal or antibacterial agents produced effects suggestive of a potential hair growth benefit., Objectives: The purpose of this 6-month, 200-patient, randomized, investigator-blinded, parallel-group clinical study was to assess the hair growth benefits of a 1% pyrithione zinc shampoo. The efficacy of a 1% pyrithione zinc shampoo (used daily), was compared with that of a 5% minoxidil topical solution (applied twice daily), a placebo shampoo and a combination of the 1% pyrithione zinc shampoo and the 5% minoxidil topical solution., Methods: Two hundred healthy men between the ages of 18 and 49 years (inclusive) exhibiting Hamilton-Norwood type III vertex or type IV baldness were enrolled. Total hair counts, the primary efficacy measure, were obtained using fibre-optic microscopy and a computer-assisted, manual hair count method. Secondary measures of efficacy included assessments of hair diameter, as well as patient and investigator global assessments of improvement in hair growth. These were based on photographs of the scalp using both midline and vertex views., Results: Hair count results showed a significant (P < 0.05) net increase in total visible hair counts for the 1% pyrithione zinc shampoo, the 5% minoxidil topical solution, and the combination treatment groups relative to the placebo shampoo after 9 weeks of treatment. The relative increase in hair count for the 1% pyrithione zinc shampoo was slightly less than half that for the minoxidil topical solution and was essentially maintained throughout the 26-week treatment period. No advantage was seen in using both the 5% minoxidil topical solution and the 1% pyrithione zinc shampoo. A small increase in hair diameter was observed for the minoxidil-containing treatment groups at week 17. Assessments of global improvements by the patients and investigator generally showed the benefit of 5% minoxidil. The benefit of the 1% pyrithione zinc shampoo used alone tended (P < 0.1) to be apparent only to the investigator., Conclusions: Hair count results show a modest and sustained improvement in hair growth with daily use of a 1% pyrithione zinc shampoo over a 26-week treatment period.

Background: Female pattern hair loss is common but estimates of its prevalence have varied widely. The relationships between the clinical diagnosis of female pattern hair loss and objective measurements of hair density and hair diameter have not previously been evaluated., Objectives: To determine the prevalence of female pattern hair loss and to relate the clinical findings to hair density and hair diameter., Methods: We examined 377 women, aged 18--99 years, who presented to a general dermatology clinic with complaints unrelated to hair growth (the unselected sample). A second group of 47 women referred with typical female pattern hair loss was included in analyses of the relationships between hair density, hair diameter and the clinical diagnosis. Hair density was measured using a photographic method. In each subject the major and minor axis diameters were measured in a random sample of 50 hairs., Results: Six per cent of women aged under 50 years were diagnosed as having female pattern hair loss, increasing to 38% in subjects aged 70 years and over. The mean +/- SEM hair density was 293 +/- 61.3 hairs cm(-2) at age 35 years, falling to 211 +/- 55.1 hairs cm(-2) at age 70 years. Hair density showed a normal distribution in the unselected sample. Most women classified as having female pattern hair loss had hair densities within the lower half of the normal distribution. The perception of hair loss was determined mainly by low hair density (ANOVA P < 0.001), but there was overlap in hair density between women classified as having Ludwig I hair loss and the no hair loss group, which was partly accounted for by differences in mean hair diameter (ANOVA P < 0.001). Low hair density was associated with fewer hairs of all diameters., Conclusions: Hair density in women is distributed as a normal variable, indicating that it is determined as a multifactorial trait. Women with female pattern hair loss have a hair density which falls below the mean but lies within the spectrum of the normal distribution, although other factors, including hair diameter, may affect the subjective impression of hair loss. The hair diameter data suggest that low hair density is not due to progressive diminution in hair follicle size and that follicular miniaturization may occur within the space of a single hair cycle.

We undertook a retrospective pathological study of 118 skin resection specimens from 101 patients with hidradenitis suppurativa. Follicular occlusion was identified in all the specimens, regardless of disease duration (1 month to 18 years), but was not noted in the axillary and inguinal skin of controls. We therefore regard follicular occlusion as an early and important feature in the pathogenesis of the disease. The presence of apoeccrine glands in axillary skin provided an in vivo model to directly observe the effects of follicular occlusion on follicle inflammation and apocrine gland destruction. In the majority of cases, active folliculitis was associated with apocrinitis and apocrine destruction, whereas apoeccrine glands, which drain directly on to the epidermal surface, appeared intact and non-inflamed. These observations provide direct evidence in an in vivo model that follicular occlusion by keratinous material, with subsequent active folliculitis and secondary destruction of the skin adnexae and subcutis, occur as an integral step in the pathogenesis of hidradenitis suppurativa.

The phototrichogram is a non-invasive technique by which, on the same precise area of the scalp, each individual hair may be identified, and its current growth phase established. This technique was used to study the duration of hair cycles in 10 male subjects, balding and non-balding, by observations at monthly intervals over a period of 8-14 years. The accumulated data served to characterize the effects of ageing in these subjects: a reduction in the duration of hair growth and in the diameter of hair shafts, most evident in the thickest hairs, and a prolongation of the interval separating the loss of a hair in telogen and the emergence of a replacement hair in anagen. These various aspects of ageing of scalp hair contribute to its progressive overall impoverishment. They resemble those observed in the course of male-pattern balding, although their development is less marked.

A pigmented follicular cyst is an infrequent variant of an epithelial cyst which has rarely been reported since it was first described about 10 years ago. The condition consists of a single pigmented lesion which occurs predominantly in adult men, and is usually located on the head and neck region. We report an example of a pigmented follicular cyst, which was located in the axilla.

The Dundee experimental bald rat (DEBR) undergoes hair loss associated with perifollicular infiltrates of mononuclear cells (MNC), a pathological characteristic of human alopecia areata (AA). To investigate further the pathogenesis of the disease in this animal model, we have studied the development, composition and extent of the perifollicular MNC infiltration in young (6-week-old), prelesional (3-month-old), active lesional, and established lesional DEBR rats, using 6-week- and 6-month-old Wistar rats as normal controls. The proportions of hair follicles showing infiltration by MNC and their main subsets were determined using immunohistochemical staining of serial cryostat sections of flank skin biopsies. There was a good correlation between the degree of leucocyte (OX-1+) infiltration of anagen hair follicles and the development of hair loss. In 6-week-old DEBR skin, there were few perifollicular cells expressing MHC class II, with positively stained dendritic cells in the dermis above the sebaceous gland. There was a sparse perifollicular distribution of CD4+ cells (W3/25) and macrophages (ED-1+). No CD8+ cells (OX-8+) were seen associated with DEBR hair follicles, and only small numbers were present in Wistar rats. In prelesional DEBR rats there was an increased perifollicular presence of MHC class II+ cells, macrophages, and particularly of CD8+ cells, with little change in CD4+ cells. Active and established lesional rats, i.e. animals with overt loss of hair, showed a significant increase in the degree of MNC infiltration and the proportion of infiltrated follicles, the majority of which were in dystrophic anagen. In the perifollicular infiltrate the CD4+:CD8+ ratio was approximately 2:1. An intrafollicular infiltrate was prominent, and was composed of CD8+ cells and macrophages, with bulbar and suprabulbar keratinocytes expressing MHC class II antigens. CD4+ cells were not detected in follicular epithelium. ICAM-1 expression correlated with MNC infiltration. These results show marked similarities to lesional human AA. They also focus on a possible active role for CD8+ cells in the pathogenesis of hair loss in the DEBR rat.

In this study we investigated the activity of the vellus hair follicle in acne. Hair growth and sebum excretion in vellus hair follicles were measured on the forehead and back of men, and on the forehead, cheek, and back of women with acne. Hair growth was assessed by computerized image analysis (phototrichogram), and sebum excretion by computer analysis using Sebutape. In patients with acne, marked differences were revealed when results were compared with recent data from healthy persons. In particular, the mean growth rate of vellus hairs was higher, whereas the percentage of anagen hairs was lower, and the duration of the anagen phase shorter in patients with acne than in healthy individuals. Hair growth and sebum excretion depended significantly (P < 0.01) on the anatomical site (forehead 414 hairs/cm2, 0.053 mm/day, 34%; back 93 hairs/cm2, 0.16 mm/day, 21%). In addition, analysis of hair growth revealed significantly higher values in females than in males for (i) percentage of anagen hairs (P > 0.01), (ii) for vellus hair length (P < 0.05), and (iii) for the duration of the anagen phase (P < 0.01). The present study demonstrates that the activity of the vellus hair follicle is influenced by acne, and vice versa, and therefore its role in the aetiopathogenesis of acne should be reconsidered.

Cosmetic causes of scarring alopecia are poorly documented. They include traction alopecia and hot-combing. Recently, another group has presented in the South London area, related to misuse of chemical hair straightening agents. Affected patients are young, female, of Afro-Caribbean origin, and typically display hair loss on the vertex of the scalp. Histology shows a pattern of fibrosis and inflammation characteristic of the physical damage seen with other cosmetic procedures. This histological pattern is distinguishable from other non-cosmetic causes of scarring alopecia.

Trichothiodystrophy (TTD) is a hair defect associated with abnormal composition of the high-sulphur proteins (HSP). HSP can be modified quantitatively (reduced amount of qualitatively normal HSP: TTD-variant) and qualitatively (TTD). In this study we show that the amino acid composition of hairs collected from the scalp of a patient with TTD-variant (donor) was preserved in hairs produced by donor scalp follicles maintained up to 6 months as grafts on to nude mice. It is the first time that an exceptionally rare, clinically and biochemically well-characterized hair dysplasia has been maintained under laboratory conditions for a long period of time. The linear growth rate of TTD-variant hairs was similar to that of control hairs grown under comparable conditions. The persistence of disease-specific abnormalities in the hair shaft indicates that the TTD-variant mutation is expressed without significant quantitative modifications, and appears independent of systemic host-related factors. This model may serve as a clinically relevant working platform for evaluating regulation of abnormal gene expression in the hair follicle under well-controlled experimental conditions.

Hair-bearing, transitional, and alopecic scalp from three males and one female with progressive pattern alopecia were examined. Ultrastructural studies disclosed measurable thickening of the follicular adventitial sheaths of transitional and alopecic zones compared with those in the non-alopecic zones. This finding was associated with mast cell degranulation and fibroblast activation within the fibrous sheaths. Immunohistochemically, control biopsies were devoid of follicular inflammation (n = 3), while transitional regions consistently showed the presence of activated T-cell infiltrates about the lower portions of follicular infundibula. These infiltrates were associated with the induction of class II antigens on the endothelial linings of venules within follicular adventitia and with apparent hyperplasia of follicular dendritic cells displaying the CD1 epitope. Inflammatory cells infiltrated the region of the follicular bulge, the putative source of stem cells in cycling follicles. The data suggest that progressive fibrosis of the perifollicular sheath occurs in lesions of pattern alopecia, and may begin with T-cell infiltration of follicular stem cell epithelium. Injury to follicular stem cell epithelium and/or thickening of adventitial sheaths may impair normal pilar cycling and result in hair loss.

A patient is described who had eruptive vellus hair cysts with and without sebaceous glands in the cyst walls. An association is suggested between eruptive vellus hair cysts and the condition of steatocystoma multiplex.

The Dundee experimental bald rat (DEBR) is reported as a model for human alopecia areata. Parallels with human alopecia areata were observed in relation to the gradual and patchy loss of hair and the penetration of both pelage and vibrissa follicles by mononuclear cells. In particular, the apparent disruption of the follicles within the precortical region of the epidermal component and consequent alterations of normal geometrical relationships between dermal and epidermal components relate directly to similar studies on human alopecia areata. In comparison with other previously described hypotrichotic rodent mutants, the DEBR rat exhibits a unique mechanism of hair loss which may provide important information regarding the pathomechanism of human alopecia areata.

We have developed a quantitative method for measuring hair growth using optical microscopy and image analysis, and have used this to investigate the rate of growth in subjects with and without alopecia. The hairs were cut from an area 7-8 mm in diameter and 24 h and 72 h later, images of the areas were obtained using an optical microscope and were recorded on a video disc. Measurements of the regrowing hairs, placed parallel to the scalp using a glass slide attached to the front of the microscope, were made using the image analyser. In subjects with little or no baldness there was a clear difference between fast-growing hairs and resting or slow-growing hairs. However, in subjects with alopecia there was no such difference and the growth rate of all the hairs showed a continuous distribution. Using this method other parameters such as the number of hairs per unit area and hair diameter as well as grouping of the hairs could be measured.

Human hair follicle mesenchyme contains a distinctive extracellular matrix which varies in volume and composition in concert with the hair growth cycle. To investigate the possibility that mesenchymal function is disturbed in alopecia areata we have studied the expression of extracellular matrix constituents in scalp biopsies from 14 patients by immunohistochemical staining for basement membrane proteins, proteoglycans and interstitial collagens. The staining patterns in follicles from non-lesional scalp were normal. Miniature anagen follicles from bald patches also showed relatively normal expression of basement membrane proteins and proteoglycans. However, in some large anagen follicles from lesional sites, there was loss of the normal staining pattern for chondroitin-6-sulphate in the dermal papilla. In lesional catagen follicles, the glassy membranes showed marked convolution and thickening. These structures stained strongly for laminin and type IV collagen but only weakly for interstitial collagens.

One hundred women who presented with diffuse alopecia, were quantitatively evaluated for hair variables and compared with 20 controls. Fifty were selected for biochemical and haematological investigations, 44 of whom also underwent endocrine evaluation. Compared to controls, significant changes in hair values were found in the frontal area of all subjects, while 84% had significant changes in the occipital area. A biphasic distribution of hair diameter was evident in subjects who had percentages of vellus hair and telogen hair less than or equal to 30 mm in length that were above the control ranges. No significant difference between the mean hormonal values of women with diffuse alopecia and controls could be found. No correlation between hair values and individual or combined hormonal levels could be established. In 18 subjects (40.9%) hormonal values were within the control ranges and these apparently normal findings were often associated with adverse hair profiles. A raised dihydrotestosterone was found in 13 subjects (29.5%) and was the most frequently elevated androgenic finding. Seventeen (34.0%) had changes in iron metabolism, while in 36 (72.0%) serum ferritin levels were below the lowest control value. All had a decrease in the percentage of hair in the anagen growth phase compared to controls. The hair changes were similar to those observed in genetic hair loss in men, a proven androgen-dependent condition. We propose that diffuse androgen-dependent alopecia is the appropriate name to describe this condition in these women.

A retrospective study was made of the histopathology of axillary skin excised from 12 patients with hidradenitis suppurativa. In the majority of cases (10 out of 12), squamous epithelium-lined structures, in the form of cysts or sinuses were identified in the dermis. Laminated keratin was present in all these structures and half of the cysts also contained hair shafts, suggesting that they are derived from hair follicles. Only a small proportion of cases (4 out of 12) displayed inflammation in apocrine glands, and in these the inflammation was also seen around eccrine glands, hair follicles and the epithelium-lined structures. However, in cases where the epithelium of the 'cysts' was disrupted, the inflammatory infiltrate appeared to be centred around these areas. These observations suggest that the squamous epithelium-lined structures, which probably represent abnormal dilated hair follicles, are a more constant diagnostic feature in hidradenitis suppurativa than inflammation of apocrine glands which appears to be a secondary phenomenon.

As average life expectancy is increasing, the ageing of skin presents a growing problem for dermatologists. When considering ageing it is important to distinguish between the effects of true biological ageing and environmental factors, such as exposure to sun. Epidermal changes associated with ageing involve the flattening of its underside, a reduction in the number of Langerhans cells and of melanocytes, and a decline in the number of melanosomes synthesized, leading to reduced pigmentation. Dermal changes involve a reduction in the collagenous and elastic fibres, fibroblasts, mast cells and macrophages, and dilation of the lymphatic channels. The number of hair follicles declines with age, but their structure remains unchanged. Ageing does not affect the sebaceous glands, but some changes occur in the exocrine sweat glands.

Transepidermal elimination is a phenomenon which occurs spontaneously in certain skin disorders in which effete connective tissue or foreign materials is expelled via the epidermis to the exterior. In order to learn how this phenomenon is effected and what factors control it, we have attempted to produce an animal model for the process. When charcoal particles are deposited subepidermally in guinea-pig flank skin transepidermal elimination occurs within 4 days and we believe that this mimics the disorder seen in man. The hair follicles became hyperplastic and were intimately involved in the reaction, some of the particles actually being expelled via the follicular lumina. The reaction has some similarities to the wound healing response.

A case of pleomorphic lipoma is described. The neoplastic tissue developed exclusively within the dermis and characteristically involved the fibrous root sheaths of hair follicles, where several layers of lamellar collagen encircled the follicles and entrapped atypical spindle and multinucleated cells. A possible origin of this tumour in the adventitial dermis is postulated.

Light and electron microscopic studies have been carried out on fifteen regrowing white anagen hair follicles from seven patients with alopecia areata. Seven bulbs showed evidence of cell injury that was concentrated in cortical keratocytes. Lower bulb matrix cells appeared undamaged though in six bulbs apoptotic degeneration was seen in the lower bulb keratocytes, perhaps indicating early catagen transformation. Melanocytes were identified in all the bulbs except those from one patient. The number of melanocytes and their melanization were much less than in the normal pigmented follicle, and pigment transfer was rarely seen. It is proposed that alopecia areata is a disease of differentiating cortical keratocytes. The failure of pigmentation in the regrowing white hair may be post-inflammatory, but the various other pigmentary features of alopecia areata, especially the sparing of senile white hairs, suggest that pigmentary mechanisms in the hair bulb are of primary importance in the pathogenesis of this disorder.

A patient with cleidocranial dysostosis developed extensive pili multigemini over the heavily bearded chin and cheek areas. Histological examination of serial sections revealed complicated follicular structures forming from two to as many eight hair shafts. Each hair is formed by a single branch of dermal papilla which is surrounded by all layers present in a normal follicle except for the outer root sheath cells. The outer root sheath surrounds the entire follicle. Irregularities in configuration of the hairs, longitudinal grooving and areas of bifurcation and re-adhesion of the hair shafts are demonstrated.

In a pilot study, 26 hirsute females were treated with medroxyprogesterone acetate (MPA). We used an ointment containing 0.2% MPA in 13 patients, subcutaneous injection of MPA into the hairy areas of the face in five patients and intramuscular injection of low doses of MPA in 13 patients, each for an average duration of 16 weeks. The best clinical result was achieved by subcutaneous injection, the next most successful was the intramuscular injection, and the least successful was the topical application. Hair diameter measurements, carried out in 12 patients, were found to be reduced by 33% on average. Serum androgen levels, measured monthly, remained unaffected by topical treatment, but were decreased by intralesional and intramuscular injection. The clinical improvement with topical therapy despite the lack of effect on serum androgen levels supports the idea that MPA works partly at the cellular level. The intralesional and systemic injection of MPA may exert an effect both by systemic androgen suppression and a local action.

A histopathological study was performed in 17 patients with alopecia areata to elucidate the changes in hair cycle dynamics. The findings confirm the view that the initial event in alopecia areata is the premature entry of anagen follicles into telogen, although some follicles survive for a time in a dystrophic anagen state. However, after re-entry into anagen takes place, growth appears to be halted in anagen III rather than anagen IV, as has previously been suggested. Follicles then return prematurely to telogen and these truncated cycles are repeated until the disease activity subsides. A new pathogenic hypothesis is presented which relates alterations in hair cycle dynamics to pathological changes within the anagen follicle and also provides an explanation for the formation of exclamation mark hairs and the non-destructive nature of the disease.

Four cases are reported in which atypical molluscum contagiosum lesions were found, arising from follicular epithelium. All the patients were adults and two had a history of atopic dermatitis. Histology showed intradermal nodules containing typical molluscum cells but lacking normal direct communication to the skin surface. This is the first description of true follicular involvement in molluscum contagiosum.

Psoriatic human hair follicle keratinocytes can be brought to culture under the same conditions as normal control hair follicle keratinocytes. In comparison with control cultures derived from non-psoriatics there are significant differences. However, no significant differences are found between cultures derived from either psoriatic involved or uninvolved skin. Some characteristics of psoriatic lesions are also encountered in the cultures. However, in contrast to the situation in a psoriatic lesion, cultures of psoriatic keratinocytes differentiate to a higher extent than comparable control cultures. A psoriatic morphology is therefore not completely formed. Whether this is due to the absence of a psoriatic dermis or to the fact that differentiation in culture is incomplete remains to be investigated.

This is a report on ten patients with follicular psoriasis. Two distinct clinical types could be distinguished. An adult form, seen especially in women, presented with widespread psoriasis in which follicular lesions occurred on both thighs as part of the efflorescence. Follicular lesions were aggregated to form isolated asymmetrical plaques on the trunks of children with inactive psoriasis. The histological findings in follicular psoriasis varied according to the age of the lesion. In the early lesion there was a marked dermal infiltrate in which the mast cells were prominent but the hair follicle appeared normal. Older lesions were found to have nucleated cells in the ostium of the follicle. These findings suggest that the hair follicle may be affected as part of psoriatic involvement of the integument.