Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders

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.

Research Advances in the Treatment of Riehl's Melanosis

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.

Systemic pigmented contact dermatitis to cobalt following ingestion of cobalamin supplement

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.

Paracrine roles of hormone receptors in Riehl's melanosis: A quantitative analysis of oestrogen and progesterone receptor expression patterns

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.

Melanogenic Properties and Expression Profiles of Melanogenic Paracrine Molecules in Riehl's Melanosis

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.

Acquired diffuse slate-grey facial dyspigmentation due to henna: an unrecognized cause of pigment contact dermatitis in Korean patients

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.

Multispectral Dermatoscopic Features of Chemical Leucoderma with Pigmented Contact Dermatitis

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.

Clinical profile of 300 men with facial hypermelanosis

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 among men.

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

These were 300 Indian men aged 18 to 74 (mean 37.35) years with 121 (40.3%) individuals aged 31-50 years. Various patterns of melasma in 230 (76.7%) patients were 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.