Clinico-investigative Study of Facial Acanthosis Nigricans.

Background: Facial acanthosis nigricans (FAN) is an underrecognized and underdiagnosed entity. The typical presentation of acanthosis nigricans (AN) seen elsewhere on the body like axillae and groins is not seen on the face, making it mimic other pigmentary disorders. Moreover, FAN is seldom not accompanied with AN on the classical sites making the diagnosis challenging. The aims of this study were to determine clinical, dermoscopic, and histopathological features of FAN and to estimate the prevalence of obesity and insulin resistance (IR) in FAN. Methods: Forty cases of FAN and forty healthy nonobese individuals with comparable ages and gender were included in the study. Body mass index, waist circumference, hip circumference, waist to hip ratio, and serum fasting lipid levels were used to evaluate obesity, whereas serum fasting insulin and Homeostatic Model of Assessment of Insulin Resistance (HOMA-IR) were used to evaluate IR. Dermoscopy was performed in all cases. Histopathological features of the skin biopsies were reviewed. Results: Out of the 40 cases, 24 were male and 16 were female. The patterns of facial pigmentation in addition to the classic pattern were a hyperpigmented band over forehead (55%), periorbital darkening (25%), perioral (10%), and generalized darkening (10%). Dermoscopy in all cases revealed linear crista cutis, sulcus cutis, and hyperpigmented dots in crista cutis. Biopsy of 20 cases showed mild hyperkeratosis, acanthosis, papillomatosis, and increase in basal melanin. Clinico-dermoscopic-histological correlation showed that milder (light brown) variants of FAN had follicular plugging and subtle sulci pattern with irregular brown globules and perifollicular pigmentation on dermoscopy and mild hyperkeratosis and hypermelanization of the basal layer with minimal acanthosis and papillomatosis on histopathology. On the other hand, chronic variants (dark brown and black) showed prominent sulci, larger brown globules, and perifollicular hyperpigmentation on dermoscopy and moderate hyperkeratosis and hypermelanization of the basal layer with moderate to severe acanthosis and papillomatosis on histopathology. Fasting blood glucose, insulin, HOMA-IR, fasting serum triglyceride, and total cholesterol were statistically significantly high in cases in comparison with controls (P-value <0.05). Conclusions: Varied clinical presentations of FAN were observed. Dermoscopy and histopathology provide a good aid. FAN may be considered as a cutaneous marker of obesity and IR. Thus, FAN should be suspected in patients presenting with facial melanosis who are obese and have AN over other sites, although FAN can also present de novo.

Dowling-Degos Disease with Follicular Involvement Associated with Hidradenitis Suppurativa: A Manifestation of Follicular Occlusion Phenomenon?

A 30-year-old female patient presented with progressive reticulate pigmentation of the neck, upper chest, back, cubital fossa, and axillae since the age of 15 years. The patient also complained of recurrent multiple tender nodules and plaques associated with sinuses and pus discharge over the axillae, groins, and buttocks which healed with scarring for 4 years. There were multiple pitted scars and hyperpigmented macules over the perioral area and cheeks. Scattered comedo-like lesions were present over the upper back, chest, cubital fossae, and buttocks. Histopathology from the pigmented lesion revealed thinning of the suprapapillary epidermis, epidermal hyperplasia with finger-like elongation of the rete ridges, and increased pigmentation of their lower part, suggestive of Dowling-Degos disease (DDD). Biopsy section from comedonal lesion showed dilated infundibulum and antler-like rete ridges suggestive of follicular DDD. We report a case of DDD with follicular involvement and hidradenitis suppurativa (HS) which is a rare association and can be explained on the basis of single underlying defect in follicular epithelial proliferation. DDD-HS has been shown to result from mutations in PSENEN, encoding a critical component of the γ-secretase complex.

Schopf-Schulz-Passarge Syndrome.

Schopf-Schulz-Passarge syndrome (SSPS) is a rare type of ectodermal dysplasia that has autosomal recessive inheritance. It is characterized by palmoplantar keratoderma, hypodontia, hypotrichosis, nail dystrophy, and multiple periocular and eyelid apocrine hidrocystomas. A 36-year-old male presented with multiple eyelid and periocular apocrine hidrocystomas, ichthyosis, palmoplantar keratoderma, hypodontia, nail dystrophy, and thin scalp hair. Skin biopsy from a periocular lesion revealed cyst lined with smooth, thin epithelium, and few areas revealed foci of decapitation secretion consistent with apocrine hidrocystoma. The patient was diagnosed with SSPS.

A study of prevalence of autoantibodies in patients with lichen planus from Mumbai, India.

BACKGROUND: Lichen planus is a common chronically relapsing autoimmune skin condition with poorly understood etiology. Apart from cellular immunity, presence of various antibodies has been hypothesized. Various studies have found the presence of serum anti-nuclear antibody, anti-mitochondrial antibody, anti-desmoglein 1 and 3 antibodies, anti-keratinocyte antibody and anti-thyroglobulin antibody in patients of cutaneous and oral lichen planus. AIM: To study the prevalence of autoantibodies and the clinical spectrum of disease in an Indian patient subpopulation with lichen planus. METHODS: A cross-sectional epidemiological study comprising 100 lichen planus patients was conducted in the dermatology outpatient department of Seth G.S Medical College and King Edward Memorial Hospital, Mumbai, Maharashtra, India. Serum concentrations of circulating anti-nuclear antibodies, anti-desmoglein 1 antibody, anti-desmoglein 3 antibody, anti-keratinocyte antibodies, anti-mitochondrial antibodies and anti-thyroglobulin antibodies were determined by indirect immunofluorescence. Pairs of groups were compared using "Student's t-test" for normally distributed continuous data. The "χ2-test" was used for the categorical variables as needed. Statistical significance was set at P < 0.05. RESULTS: It was found that 65 (65%) patients showed the presence of at least one of the six autoantibodies that we studied, while 35 (35%) tested negative for all six of them. Positivity of anti-keratinocyte antibody in 26 (26%), anti-nuclear antibody in 22 (22%), anti-desmoglein 1 antibody in 19 (19%), anti-desmoglein 3 antibody in 16 (16%), anti-mitochondrial antibody in 9 (9%) and anti-thyroglobulin antibody in 6 (6%) patients was detected. It was observed that 55 (71.4%) patients of cutaneous lichen planus, 6 (46.1%) patients of mucosal lichen planus and 4 (40%) patients of cutaneous and mucosal lichen planus overlap showed presence of at least one autoantibody. CONCLUSION: This study provides the serological parameters of a population of lichen planus from western India. Presence of autoantibodies in lichen planus suggests the possible role of humoral immunity in lichen planus. Identifying antibodies linked to lichen planus may help in identifying suitable diagnostic tests and therapeutic targets. Well-controlled studies with larger sample size are the need of the hour to confirm the role of humoral immunity in lichen planus. LIMITATIONS: Studies with a larger number of patients as well as controls should be undertaken to further evaluate the role of autoantibodies in lichen planus.