Search

Background: Millions of people are infested by head lice every year. However, louse transfer between hosts is not well-understood. Our goals were to determine: (1) which stages were most likely to disperse and why, (2) the likelihood of fomites transmission, and (3) if host blood gender affects louse development., Methods: Various life stages of lice at differing densities were permitted to cross over a 15-cm hair bridge placed between two artificial blood-feeding arenas. Louse transfer caused by hot air movements, combing, toweling, and passive transfer to fabric was investigated. The ability of lice to oviposit on different foreign substrates and the hatching potential of eggs intermittently incubated for 8 h/night on a host were likewise investigated. Louse in vitro development following feeding on human female or male donor blood was compared., Results: Adult lice were the most likely to disperse. Neither population density nor hunger significantly affected dispersal tendencies. Lice were dislodged by air movement, combs and towels, and passively transferred to fabric within 5 min. Females oviposited on a variety of substrates and 59% of eggs incubated for 8 h/night hatched after 14-16 days. There was no survivorship difference between lice artificially fed on female vs. male blood., Conclusions: Adult lice are the most mobile, indicating that they are most likely to initiate new infestations. Although head-to-head contact may be the primary route of transmission, less direct routes involving fomites may play a role and need further evaluation. Blood-borne factors do not appear to cause any gender-biased host preference.

Background: The scalp is a problematic area in psoriasis where treatment is often difficult. The lesions often extend beyond the hairline to involve the forehead, neck and sensitive facial skin. Topical corticosteroids and potentially irritant topical preparations have only limited utility in these sensitive areas. Most of the patients additionally suffer from psychosocial problems due to the visibility of lesions., Objective: The aim of this multicenter, prospective, randomized, double-blind study, was to assess efficacy, safety and tolerability of once daily tacalcitol emulsion (4 micro g/g) compared to placebo in the treatment of scalp psoriasis., Methods: To determine efficacy, safety and tolerability, 273 patients with mild to moderate scalp psoriasis were treated over a 8-week period. Response to treatment was evaluated using the sum score of erythema, infiltration and scaling. Global improvement of psoriasis was rated by the investigators and the patients using a 5-point scale. In addition the single scores of erythema, infiltration and scaling were assessed by the investigators, and the patients were asked to evaluate the intensity of itching and scaling over the treatment period., Results: Tacalcitol was significantly superior to placebo in reducing the severity of scalp psoriasis. At the end of the study, the median sum score decreased by 53% in the tacalcitol group and was significantly better than placebo with 30% (p<0.0001). Global assessment of improvement was significantly greater in the tacalcitol group in both investigator and patient evaluation. 80% of patients on tacalcitol showed improvement to clearance and was statistically significant better than placebo (p <0.0001) in the investigator rating after 8 weeks. Tacalcitol was significantly superior to placebo in reducing erythema, scaling and infiltration, and in the patient assessment in reducing scalp scaling and itching. Treatment was very well tolerated. Local reactions were transient and uncommon. Their incidence was similar in both treatment groups. No serious side effects were reported, including those relating to calcium homeostasis or vitamin D(3) metabolism. No changes in mean levels of serum calcium, parathyroid hormone (PTH), calcitriol and in 24h-urinary excretion were observed., Conclusion: The results of this study indicate that topical application of tacalcitol (4 micro g/g) emulsion once daily is an effective, safe and very well- tolerated treatment for scalp psoriasis.

Background: In case the shedding telogen hair is not replaced in time by a terminal anagen hair, an empty space results., Objective: To verify whether the phenomenon is present in prepubertal subjects., Methods: From July 1996 to May 1997, an 8-year-old boy was submitted monthly to the phototrichogram technique. Sixty hairs were monitored throughout the study., Results: 52% of all studied hairs were terminal anagen hairs throughout the study and additionally 22% were in a regular hair cycle. Vellus hairs and empty spaces were observed in 18 and 8% of follicles, respectively. In 2% of hairs, vellus hairs and empty spaces were associated., Conclusions: Vellus hairs and empty spaces are present even in children. Without gonadal androgens and expression or induction of 5alpha-reductase in the prepubertal scalp, they are unlikely to herald androgenetic alopecia (AGA) but could reflect a physiological phenomenon of 'true resting' of a small proportion of scalp hair. Androgens may increase the phenomenon which may account in part for AGA development.

Background: Acne keloidalis (AK) is an important cause of morbidity in Nigeria and accounts for 1.3% of patients with skin conditions in a Nigerian dermatology clinic. Treatment is usually unsatisfactory because the etiopathogenesis is unclear., Methods: A prospective clinico-pathological study was carried out to identify predisposing factors, viable treatment modalities, and prognostic indicators., Results: The study suggested that AK is associated with the male gender seborrheic constitution, early reproductive years, and increased fasting blood testosterone concentration. Features that may predispose to the vastly predominant occipital location of the lesions include increased mast cell density and dilatation of dermal capillaries., Management: The main aims are diagnosis of early papules and avoidance of physical and chemical traumatizing agents. Retinoic acid analogs and antiandrogens may be helpful., Conclusions: The widespread use of irritating physical and chemical traditional treatment remedies and delay in seeking medical attention--AK is typically asymptomatic--contribute to the relatively advanced nature of the disease at the time of presentation to the specialist.

'Eosinophilic pustular folliculitis", first described by Ofuji and co-workers in 1970, is obviously a new entity, not only confined to Japan. Recently, there was a case reported from Sweden; we present here the first observation in the FRG. The disease is characterized by eruptions of aggregated pustules, containing numerous eosinophils, and by blood eosinophilia. In our patient the disease first appeared on the scalp, leading to scarring alopecia. Since in our and in some other patients the lesions were not limited to the follicles, we feel that the term 'sterile eosinophilic pustulosis" is more appropriate to reflect the clinical picture. For differential diagnosis Morbus Duhring and M. Sneddon-Wilkinson have to be considered. "Sterile eosinophilic pustulosis" differs from these mainly because of the eosinophilic infiltrations deep in the dermis. Immunofluorescence tests are negative. Treatment with DADPS may be helpful.