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Liuli Xu, Qing Huang, Ting Wu, Yunzhu Mu Department of Dermatology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of ChinaCorrespondence: Yunzhu Mu, Department of Dermatology, Affiliated Hospital of North Sichuan Medical College, Nanchong, People’s Republic of China, Email hymyz@126.comAbstract: Riehl’s melanosis (RM) is a contact photodermatitis, with fast progressive gray-brown skin pigmentation as the main manifestation, which can seriously affect the psychology and physiology of patients. Currently, although the etiological factors of Riehl’s melanosis is still be unknown, the existing literature proves clearly the cause of it is related to the contacting with suspected allergens. For decades, there has been no standard method for the treatment of RM, but with both conventional drug therapy and laser therapy having been attempted. Topical application of bleaching agents is mainly used as an auxiliary treatment modality. The laser treatment modality remains a hot spot, among which Q-switched Nd:YAG laser is well received for RM. Positive outcomes have been achieved by the combined treatment modalities attempted in recent years also achieve positive outcomes. The purpose of this paper is to review and summarize recent advances in the treatment of the disease.Keywords: Riehl’s melanosis, pigmented contact dermatitis, therapy

Background: Facial melanosis is a common clinical problem and results in impaired quality of life. Aims: The aim of the study was to compare the quality of life in female patients suffering from melasma and nonmelasma facial melanosis (NMFM) using melasma quality of life (MELASQOL) and dermatology life quality index (DLQI). Methods: It was a prospective cross-sectional study conducted in a dermatology outpatient department of tertiary care center. Modified melasma area severity index (mMASI), MELASQOL, and DLQI were calculated in female patients meeting inclusion criteria of the study. The statistical analysis was performed using statistical package for social sciences (SPSS version 20; Chicago, IL, USA). Categorical data are presented as number with percentage and continuous data as mean with standard deviation. Quantitative data were compared using independent t test and categorical data using Chi-square test. All statistical tests were two sided and were performed at a significance level of α = 0.05. Results: A total of 119 patients were included in the study and consisting of 50 (42%) patients with melasma and 69 (58%) patients with NMFM. The impairment of quality of life was more in NMFM when compared with melasma group. The severity of pigmentation (mMASI) did not show any significant correlation with MELASQOL or DLQI in either of the groups. There was strong correlation between DLQI and MELASQL (Spearman rho = 0.886; P < 0.001). Conclusion: Facial melanosis impacts quality of life adversely. The impact of NMFM is more when compared with melasma. MELASQOL and DLQI should be performed in these patients to understand true impact of these diseases on quality of life. [ABSTRACT FROM AUTHOR]

Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation. [ABSTRACT FROM AUTHOR]

A chemical peel is chemexfoliation, a process of application of a chemical substance to the skin that causes controlled chemical destruction of the epidermis with or without part of the dermis leading to skin regeneration and remodeling. It can be classified depending upon the depth of penetration into superficial, medium, and deep peels. Among various indications, peels can be used to enhance treatment within a variety of conditions including skin- rejuvenation, inflammatory disorders like acne, rosacea, acne scar, and pigmentary disorders like melasma, freckles, lentigens, dyschromia, and post-inflammatory pigmentation. We did a chemical peel for six patients with facial melanosis, diagnosed with Riehl melanosis. All patients had visible clinical improvement. Detailed history and informed consent were taken both for photographs and procedures from all patients. [ABSTRACT FROM AUTHOR]

Background: Facial pigmentation includes various entities such as melasma, lichen planus pigmentosus (LPP), and pigmented contact dermatitis. The pathogenesis may involve certain allergens, which may be responsible for causing a disturbance in the dermoepidermal junction. The elimination of such inciting allergens may aid in the successful treatment of these patients. Objective: The aim was to detect contact allergens with patch and photopatch testing in facial pigmentary disorders. Methods: Fifty patients with facial pigmentary disorders were enrolled. After taking a demographic profile and detailed clinical history and performing an examination, patch and photopatch testing was done using a common suspected allergen series. Results: Out of the fifty patients tested, 28 (56%) showed a positive patch test, while 2 (4%) showed a positive photopatch test. The most common allergen found was a fragrance mix in 17 (34%) patients, followed by paraphenylenediamine (PPD) in 11 (22%). Other allergens showing positivity were nickel sulfate, benzocaine, parthenium, benzophenone-3, octyl methoxycinnamate, etc. Conclusion: Patients with facial pigmentation may have an underlying component of contact dermatitis, which may be a causative or aggravating factor. The avoidance of these allergens may help in increasing the efficacy of treatment in these patients. [ABSTRACT FROM AUTHOR]

Background: Paucity of literature and non consensus on clinicohistopathological features amongst the nonmelasma facial melanosis for example lichen planus pigmentosus (LPP), pigmented contact dermatitis (PCD), macular amyloidosis, acanthosis nigricans, pigmented demarcation line, post inflammatory hyperpigmentation, etc., make them difficult to diagnose and equally challenging to treat. Materials and Methods: It was a prospective, uncontrolled study, conducted at tertiary hospital at eastern India in 100 patients presenting with facial hyperpigmentation who agreed to undergo 3 mm skin biopsy during Jan 2014 to Jun 2015. Cases of melasma were excluded by clinical, Woods lamp examination and if required dermoscopy. Details of history, physical examination, histopathological examination, and Immunohistochemical studies were recorded. Melan A was used as melanocytic differentiation marker while CD4, CD8 were used as inflammatory markers. Mean ± SD, chi-square test or Fisher’s exact test, degree of agreement by Cohen’s Kappa were calculated. P-value was considered significant if ≤0.05. Results: 44 males and 56 females (56%) (M: F=1:1.24) with mean age of 45.98 years and median duration of illness of 28 months (5 months-13 years) were studied. Out of 43 confirmed cases of PCD, 16 had associated hypothyroidism (chi square 6.11, P-value 0.0134). Maximum patients belonged PCD (n = 47) followed by LPP (n = 27). Maximum concordance of clinical and histopathological diagnosis was present in PCD and LPP (Cohen kappa more than 0.9). Epidermal atrophy and band like inflammatory infiltrate were statistically significant features in LPP (P < 0.001). There was no histopathological and immunohistochemical correlation. Overall, clinical histopathological concordance rate was 77%. Conclusion: Subset of nonmelasma facial melanosis is difficult to diagnose clinically which require further confirmation by histopathological examination. Small number of patients in other groups apart from PCD and LPP and uncontrolled study were major limitations of this study.

Keywords: acquired dermal macular hyperpigmentation; CAS no. 302776-68-7; case report; cinnamal; cinnamyl alcohol; diethylamino hydroxybenzoyl hexyl benzoate; frontal fibrosing alopecia; lichen planus pigmentosus; pigmented contact dermatitis; sunscreens EN acquired dermal macular hyperpigmentation CAS no. 302776-68-7 case report cinnamal cinnamyl alcohol diethylamino hydroxybenzoyl hexyl benzoate frontal fibrosing alopecia lichen planus pigmentosus pigmented contact dermatitis sunscreens 287 289 3 08/16/22 20220901 NES 220901 We report a patient with pruritic hyperpigmentation of the face and neck, who subsequently developed frontal fibrosing alopecia (FFA), and who was shown to be sensitized to fragrances and to the ultraviolet (UV)-filter diethylamino hydroxybenzoyl hexyl benzoate. Co-sensitizations to cinnamal and cinnamyl alcohol have recently been described in patients' photo-allergic to ketoprofen,10 the latter also being a benzophenone derivative, similar to benzophenone-3 (oxybenzone) and diethylamino hydroxybenzoyl hexyl benzoate (Figure S1). Case report, acquired dermal macular hyperpigmentation, CAS no. 302776-68-7, diethylamino hydroxybenzoyl hexyl benzoate, cinnamal, cinnamyl alcohol, frontal fibrosing alopecia, lichen planus pigmentosus, pigmented contact dermatitis, sunscreens. [Extracted from the article]

Background: Paucity of literature and non consensus on clinicohistopathological features amongst the nonmelasma facial melanosis for example lichen planus pigmentosus (LPP), pigmented contact dermatitis (PCD), macular amyloidosis, acanthosis nigricans, pigmented demarcation line, post inflammatory hyperpigmentation, etc., make them difficult to diagnose and equally challenging to treat. Materials and Methods: It was a prospective, uncontrolled study, conducted at tertiary hospital at eastern India in 100 patients presenting with facial hyperpigmentation who agreed to undergo 3mm skin biopsy during Jan 2014 to Jun 2015. Cases of melasma were excluded by clinical, Woods lamp examination and if required dermoscopy. Details of history, physical examination, histopathological examination, and Immunohistochemical studies were recorded. Melan A was used as melanocytic differentiation marker while CD4, CD8 were used as inflammatory markers. Mean ± SD, chi-square test or Fisher's exact test, degree of agreement by Cohen's Kappa were calculated. P-value was considered significant if =0.05. Results: 44 males and 56 females (56%) (M: F=1:1.24) with mean age of 45.98 years and median duration of illness of 28 months (5 months-13 years) were studied. Out of 43 confirmed cases of PCD, 16 had associated hypothyroidism (chi square 6.11, P-value 0.0134). Maximum patients belonged PCD (n= 47) followed by LPP (n=27). Maximum concordance of clinical and histopathological diagnosis was present in PCD and LPP (Cohen kappa more than 0.9). Epidermal atrophy and band like inflammatory infiltrate were statistically significant features in LPP (P < 0.001). There was no histopathological and immunohistochemical correlation. Overall, clinical histopathological concordance rate was 77%. Conclusion: Subset of nonmelasma facial melanosis is difficult to diagnose clinically which require further confirmation by histopathological examination. Small number of patients in other groups apart from PCD and LPP and uncontrolled study were major limitations of this study. [ABSTRACT FROM AUTHOR]

Abstract Systemic contact dermatitis (SCD) is a condition occurring in previously sensitized individuals after systemic re‐exposure to the same or cross‐reacting substance. Pigmented systemic contact dermatitis after intake of cobalt containing diet has never been reported.

Systemic contact dermatitis (SCD) is a condition occurring in previously sensitized individuals after systemic re‐exposure to the same or cross‐reacting substance. Pigmented systemic contact dermatitis after intake of cobalt containing diet has never been reported. [ABSTRACT FROM AUTHOR]

2 Bishnoi A, Vinay K, Parsad D, Handa S, Saikia UN, Sendhil Kumaran M. Contact sensitization to hair colours in acquired dermal macular hyperpigmentation: results from a patch and photo-patch test study of 108 patients. Allergic contact dermatitis, case report, frontal fibrosing alopecia, gallates, pigmented contact dermatitis, propolis, acquired dermal macular hyperpigmentation, ethylhexyl salicylate, lichen planus pigmentosus, Magnolia officinalis bark extract Keywords: acquired dermal macular hyperpigmentation; allergic contact dermatitis; case report; ethylhexyl salicylate; frontal fibrosing alopecia; gallates; lichen planus pigmentosus; Magnolia officinalis bark extract; pigmented contact dermatitis; propolis EN acquired dermal macular hyperpigmentation allergic contact dermatitis case report ethylhexyl salicylate frontal fibrosing alopecia gallates lichen planus pigmentosus Magnolia officinalis bark extract pigmented contact dermatitis propolis 434 436 3 04/14/22 20220501 NES 220501 Frontal fibrosing alopecia (FFA) and lichen planus pigmentosus (LPP) frequently coexist.1 The umbrella term "acquired dermal macular hyperpigmentation (ADMH)" encompasses disorders with clinicopathological overlap such as LPP and pigmented contact dermatitis.2 Contact sensitization has been described in the contexts of both FFA and ADMH.2-4 CASE REPORT A woman with Fitzpatrick skin phototype IV and hypothyroidism developed pruritic macular hyperpigmentation with punctate hypopigmentation symmetrically on her forehead (Figure 1A) at age 45 which she related to hair dyes. [Extracted from the article]

The incidence of Riehl's melanosis (RM) is most common in the fifth or sixth decade of life with a female preponderance. As the skin is regarded a non‐reproductive organ on which sex steroid hormones act, a possible relationship between the pathogenesis of RM and sex steroid hormone receptors can be inferred. This study intended to evaluate the expression profile of oestrogen receptor (ER)β and progesterone receptor (PR) in RM. Twelve lesional and perilesional normal‐appearing skin samples of RM patients and the skin of 12 healthy controls were retrieved for the analysis. Real‐time PCR analysis and immunohistochemical studies were conducted for ERβ and PR, respectively. The lesional and perilesional normal‐appearing skin of 12 patients with RM and the skin of 12 healthy controls were retrieved for the analysis. Interestingly, the dermal ERβ immunostaining intensity was increased more in lesional skin than in perilesional skin. When compared to healthy controls, increased expression of ERβ and PR mRNAs was observed in the lesional skin of patients with RM. Of note, epidermal and dermal ERβ and dermal PR expressions showed increased staining intensities in the lesional skin of RM patients compared with healthy controls. The altered expression of ERβ and PR in RM supports the possible role of these hormone receptors in the pathogenesis of RM. [ABSTRACT FROM AUTHOR]

Chemical leukoderma is characterized by pigment loss on constant exposure to chemical agents. Its association with pigmented contact dermatitis is rare. Here, we report a 40-year-old female presenting with depigmented macule with surrounding hyperpigmentation over the upper forehead. We used a multispectral dermatoscope by which decreased pigment network was better visualized with blue light, and gray granular dots were better appreciated with yellow light. Shorter wavelengths delineate epidermal features better whereas longer wavelengths highlight dermal features in multispectral dermatoscopy.

Pigmented contact dermatitis (PCD) is a noneczematous variant of contact dermatitis, characterized clinically by hyperpigmentation with little or no signs of dermatitis. The commonly implicated agents causing PCD include cosmetics like fragrances, lipsticks and kumkum, preservatives, optical whiteners, benzyl salicylate and metallic compounds like nickel sulphate and nickel oxide. We present a case of PCD in a 45-year old textile factory worker, who presented with gradually progressive asymptomatic hyperpigmentation of the face which started after he started working in a textile factory. Patch test revealed sensitization to p-Paraphenylenediamine, thereby confirming the diagnosis of PCD to p-Paraphenylenediamine.

Riehl’s melanosis is a hyperpigmentary disorder that occurs predominantly on the face and neck. To date, the pathogenesis of Riehl’s melanosis with regards to the melanogenic properties and paracrine melanogenic molecules has not well been studied. This study was aimed to provide a novel perspective on the pathogenesis of Riehl’s melanosis by identifying the relevant paracrine melanogenic molecules in Riehl’s melanosis. Skin biopsies were performed on lesional and normal-appearing perilesional skin of 12 patients with Riehl’s melanosis and 12 age- and sex-matched healthy controls. Histopathological and immunohistochemical staining for paracrine melanogenic molecules was analyzed. The major histopathological findings of Riehl’s melanosis were basal hyperpigmentation, melanocyte proliferation, interface change, dermal pigmentary incontinence, vascular proliferation, and dermal inflammation. Dermal expression intensities of stem cell factor (SCF) and c-kit were increased in the lesional skin of Riehl’s melanosis. In addition, increased expression of epidermal and dermal ET-1 was also observed in the lesional skin of Riehl’s melanosis. Increased tissue expressions of SCF, c-kit, and ET-1 in Riehl’s melanosis support the role of these paracrine melanogenic molecules in the pathogenesis of Riehl’s melanosis. The findings from this study might present useful information on the pathogenetic mechanism of Riehl’s melanosis.

Background: Facial hypermelanosis is a significant cause of cosmetic disfigurement, social embarrassment and psychological morbidity affecting quality of life. Objective: To study clinicoepidemlogic patterns of facial hypermelanoses amongmen. Material and Methods: Medical records of all adult males presenting with facial hypermelanoses were analyzed for this retrospective cross sectional study for demographic details, duration, cosmetic usage, sun exposure, drug intake, infections, systemic or cutaneous diseases, and family history of hypermelanotic dermatosis. Laboratory investigations and skin biopsy were performed when deemed necessary. Results: Thesewere 300 Indianmen aged 18 to 74 (mean 37.35) yearswith 121 (40.3%) individuals aged 31-50 years. Various patterns of melasma in 230 (76.7%) patientswere the major cause of facial hypermelanosis. Periorbital hypermelanosis was observed in 32 (10.7%), freckles and lentigens in 26 (8.7%), acanthosis nigricans in 12 (4%) and lichen planus pigmentosus in 10 (3.3%), pigmented cosmetic contact dermatitis in 7, and nevus of Ota in 6 persons. The 71 (30.8%) patients with melasma had a history of frequent sun exposure, 9 (3.9%) patients had systemic comorbidities. Family history of periorbital melanosis was present in 7 (21.8%), personal or family history of atopy in 5 (15.6%) patients. Acanthosis nigricans was associated with obesity in 9 (75%) of patients and with diabetes mellitus in 4 (33.3%) cases. Conclusions: Melasma, periorbital hypermelanosis, acanthosis nigricans and lichen planus pigmentosus remain the predominant causes for facial hypermelanosis in men. [ABSTRACT FROM AUTHOR]

Keywords: case report; personal protective equipment; pigmented contact dermatitis; polyester; polyurethane; Riehl's melanosis EN case report personal protective equipment pigmented contact dermatitis polyester polyurethane Riehl's melanosis 720 721 2 11/18/21 20211201 NES 211201 Riehl's melanosis (RM), also known as pigmented contact dermatitis, is characterized by a brown to gray pigmentation on the face and neck. Case report, personal protective equipment, pigmented contact dermatitis, polyurethane, polyester, Riehl's melanosis. [Extracted from the article]

Chemical leukoderma is characterized by pigment loss on constant exposure to chemical agents. Its association with pigmented contact dermatitis is rare. Here, we report a 40-year-old female presenting with depigmented macule with surrounding hyperpigmentation over the upper forehead. We used a multispectral dermatoscope by which decreased pigment network was better visualized with blue light, and gray granular dots were better appreciated with yellow light. Shorter wavelengths delineate epidermal features better whereas longer wavelengths highlight dermal features in multispectral dermatoscopy. [ABSTRACT FROM AUTHOR]

Pigmented contact dermatitis (PCD) is a noneczematous variant of contact dermatitis, characterized clinically by hyperpigmentation with little or no signs of dermatitis. The commonly implicated agents causing PCD include cosmetics like fragrances, lipsticks and kumkum, preservatives, optical whiteners, benzyl salicylate and metallic compounds like nickel sulphate and nickel oxide. We present a case of PCD in a 45-year old textile factory worker, who presented with gradually progressive asymptomatic hyperpigmentation of the face which started after he started working in a textile factory. Patch test revealed sensitization to p-Paraphenylenediamine, thereby confirming the diagnosis of PCD to p-Paraphenylenediamine. [ABSTRACT FROM AUTHOR]

Pigmentary complication by contact immunotherapy (CI) for alopecia areata (AA) has been reported but its pathophysiology remains unknown. To characterize pigmentary complication by CI and its pathophysiology, we examined the incidence of hyperpigmentation in 186 consecutive patients treated with CI using diphenylcyclopropenone. From clinical data of AA totalis (AAT) or universalis (AAU) patients ( n = 78), we studied the correlations between this complication and age, sex, atopic background, duration and treatment responsiveness, duration of CI, final concentration of diphenylcyclopropenone and administration of anti-histamines by χ2-test or Mann-Whitney U-test. Additionally, the histopathology of pigmentation was studied. As a result, 11 (5.91%) of the 186 patients had hyperpigmentation in this series. All of them had AAT or AAU, suggesting that the pigmentation is apt to occur in severe AA. When the AAT or AAU patients with ( n = 11) and without hyperpigmentation ( n = 67) were compared, those with pigmentation showed poorer responsiveness to CI ( P < 0.05) but no significant tendency for other factors. Histopathologically, skin specimens showed lichenoid or vacuolar interface dermatitis with necrotic keratinocytes and dermal melanophages, consistent with pigmented contact dermatitis (PCD). Together, pigmentary complication by CI corresponds to PCD from therapeutic sensitizer, representing clinical indicator of poor responsiveness. [ABSTRACT FROM AUTHOR]

We studied 39 patients with erythema-dyschromicum-perstans-Iike dermatitis seen at Changuinola Hospital in Panama. They were compared with 41 controls. The 2 groups were native field workers of the banana plantations exposed to many pesticides. In 34 patients, there was a positive patch test reaction to 2,4,5,6-1,3-tetrachloroisophthalonilnitrile (chlorothalonil, TCPN) 0.001% in acetone. In 39 cases, biopsies showed a lichenoid tissue reaction compatible with a chronic pigmented dermatitis or erythema-dyschromicum-perstans-like dermatitis. Chlorothalonil is possibly the cause of the pigmented dermatitis observed in the 39 banana farm workers studied. Until additional studies are carried out, we consider this a possible rather than definite cause-and-effect relationship. [ABSTRACT FROM AUTHOR]

Eight patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R were patch tested with purified Sudan I and its several chemical analogues. Positive reactions were observed to Sudan I, Orange SS, Brilliant Lake Red R, Vacanceine Red, Yellow OB and Sudan II. Negative patch tests were obtained with Toluidine Red, Permanent Orange, Lithol Red and Sudan III. We found that the commercial Brilliant Lake Red R which had been said to be the most important causative agent of pigmented contact dermatitis, contained Sudan I as a major impurity. The patients reacting to Brilliant Lake Red R always gave a positive reaction to Sudan I, but those reacting to Sudan I did not always give a positive reaction to Brilliant Lake Red R. This suggests that Sudan I is a potent sensitizer and may induce contact sensitivity and that Brilliant Lake Red R itself is a weak sensitizer or a cross-reacting substance. [ABSTRACT FROM AUTHOR]

Eight patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R were patch tested with purified Sudan I and its several chemical analogues. Positive reactions were observed to Sudan I, Orange SS, Brilliant Lake Red R, Vacanceine Red, Yellow OB and Sudan II. Negative patch tests were obtained with Toluidine Red, Permanent Orange, Lithol Red and Sudan III. We found that the commercial Brilliant Lake Red R which had been said to be the most important causative agent of pigmented contact dermatitis, contained Sudan I as a major impurity. The patients reacting to Brilliant Lake Red R always gave a positive reaction to Sudan I, but those reacting to Sudan I did not always give a positive reaction to Brilliant Lake Red R. This suggests that Sudan I is a potent sensitizer and may induce contact sensitivity and that Brilliant Lake Red R itself is a weak sensitizer or a cross-reacting substance. [ABSTRACT FROM AUTHOR]

Competing Interests: Competing interests: The authors have no conflicts of interest to disclose.

Riehl's melanosis is a hyperpigmentary disorder that occurs predominantly on the face and neck. To date, the pathogenesis of Riehl's melanosis with regards to the melanogenic properties and paracrine melanogenic molecules has not well been studied. This study was aimed to provide a novel perspective on the pathogenesis of Riehl's melanosis by identifying the relevant paracrine melanogenic molecules in Riehl's melanosis. Skin biopsies were performed on lesional and normal-appearing perilesional skin of 12 patients with Riehl's melanosis and 12 age- and sex-matched healthy controls. Histopathological and immunohistochemical staining for paracrine melanogenic molecules was analyzed. The major histopathological findings of Riehl's melanosis were basal hyperpigmentation, melanocyte proliferation, interface change, dermal pigmentary incontinence, vascular proliferation, and dermal inflammation. Dermal expression intensities of stem cell factor (SCF) and c-kit were increased in the lesional skin of Riehl's melanosis. In addition, increased expression of epidermal and dermal ET-1 was also observed in the lesional skin of Riehl's melanosis. Increased tissue expressions of SCF, c-kit, and ET-1 in Riehl's melanosis support the role of these paracrine melanogenic molecules in the pathogenesis of Riehl's melanosis. The findings from this study might present useful information on the pathogenetic mechanism of Riehl's melanosis. [ABSTRACT FROM AUTHOR]

This article discusses a case study related to pigmented photoallergic contact dermatitis from musk ambrette. A 52-year-old male, working as a car driver, had 4-year old history of facial dermatitis. Only diffuse cutaneous brownish pigmentation restricted to the beard area was observed. Facial photosensitivity followed within few months, the use of a new after-shave lotion containing musk ambrette. This fragrance ingredient of male cosmetics is often reported as a cause of allergic or photoallergic contact dermatitis and sometimes persistent light reaction. Positive photopatch tests with residual pigmentation strongly suggest that musk ambrette present in the after-shave lotion was the agent of this pigmented photoallergic contact dermatitis.

Henna is a vegetable hair dye that can be used by individuals who are sensitized to oxidative dyes due to low allergenicity. The reported incidence of slate-grey facial dyspigmentation following the use of henna hair dye is extremely rare. This study aimed to identify the clinical, dermoscopic, and histopathological features of slate-grey facial dyspigmentation following the use of henna hair dye in Korean patients. We identified all patients who presented with slate-grey facial dyspigmentation following usage of henna hair dye. Patients were further evaluated for clinical, dermoscopic, and histopathological findings along with their patch test results. All 11 patients were females with Fitzpatrick's skin phototype III or IV. Prominent slate-grey-coloured dyspigmentation on the lateral side of the face and neck was most common in eight (72%) patients. Under dermoscopic examination, a pseudo-network with grey dots was observed in all patients. Histopathological examination revealed liquefaction degeneration of the epidermal basal layer and pigmentary incontinence in the papillary dermis in all patients. The diagnosis of pigmented contact dermatitis following usage of henna was made based on the clinical, dermoscopic, and histopathological findings in all patients. Pigmented contact dermatitis associated with henna occurs mostly in middle-aged women and requires long-term treatment. Therefore, careful attention should be paid when henna is used to dye hair in this age group.

The article presents a case study of a 54-year-old Spanish woman who presented with actiniclentigines on her arms and forearms, admitted to having used a fungal metabolic product Kojicol Plus for 5 years to lighten the lesions. She was patch tested with kojic acid 1% aqua and the Kojicol Plus, and the results were negative. However, the study reveals that in contact dermatitis, hyperpigmentation often occurs without any clinical dermatitis.

The article describes a case of pigmented cosmetic dermatitis in a 38-year-old Japanese patient caused by an allergen, dipentaerythritol fatty acid ester from her lipstick. The patient developed hyperpigmentation and a burning and itchy swelling on her lips after using a new type of lipstick. After she stops using the lipstick, the patient's pigmentation on her lips faded spontaneously.

The article focuses on the co-existence of contact leukoderma and pigmented contact dermatitis attributed to Clematis chinensis Osbeck. Contact leukoderma is characterized by loss of pigment on exposure to chemical agents. Pruritic erythema had been noted following each use of Clematis chinensis osbeck about twice weekly for 5 months before hyper- and hypopigmentation appeared.

Examines a patient who developed pigmented contact dermatitis after exposure to a 5% minoxidil. Discussion of the vaso-dilatory properties of the drug; Importance of recognizing the other side effects of the substacne.