Acquired reactive perforating collagenosis, a rare entity at uncommon site.

Acquired reactive perforating collagenosis (ARPC), rare disorder characterized by transepidermal elimination (TEE) of collagen fibers, is seen in adult diabetics. Genetic predisposition, familial aggregation, trauma, bites and scratching are implicated. Diabetics develop microvascular diseases leading to intense pruritus causing repeated micro trauma leading to necrosis of connective tissue of dermis, causing TEE. Isolated papules, plaques and nodules with central keratotic plugs, are mostly seen on extensor surfaces of limbs but trunk and face may be involved. Histopathology shows extrusion of abnormal collagen fibers through epidermis. Multiple treatment modalities show variable response. A 52 year old diabetic female had multiple, itchy, well defined, erythematous papules and plaques with central adherent crusting on lower back since 1 month. Histopathology showed cup shaped epidermal depression filled with plug of altered collagen, acanthotic epidermis with hyperkeratosis and parakeratosis. Underlying epidermis was thin with fine slits through which vertically oriented basophilic collagen fibers were extruded.

Patch Testing as a Corroborative and Diagnostic Tool in Patients Suspected of Contact Allergen Induced Facial Melanosis.

BACKGROUND: Hypermelanosis involving predominantly the face and neck is relatively common and often presents a complex diagnostic problem. OBJECTIVE: To study the patterns of facial melanosis in Indian skin and assess the importance of patch testing as a corroborative tool in the diagnosis of facial melanosis. SUBJECTS AND METHODS: A total of 50 patients who consented to the study and satisfied the inclusion and exclusion criteria were incorporated in the study. These patients were subjected to a detailed history, clinical, dermoscopic, and histopathological evaluation. Patch testing using the universal series, cosmetic series, and photopatch was done on those who satisfied the inclusion criteria. Suspected allergen "as is" patch testing was done in selected cases. RESULTS: Facial melanosis as a result of contact dermatitis is a common entity and was seen in the age group of 18-70 years in both the sexes with male to female ratio of 6.5:2.5 indicating a male preponderance. The most common dermoscopic finding was the presence of reticular pigment network seen in 33 (66%) cases. Histopathology showed increased basal melanin in 56% and pigment incontinence in 26% of the cases. The commonest allergen in men was found to be potassium dichromate (15%), while in females it was nickel (20%). Photopatch test was done for all the patients and was positive in five cases (10%). Suspected allergen "as is" patch testing was negative in all the cases. CONCLUSIONS: Facial melanosis as a result of contact dermatitis can be confused with other acquired dermatological conditions causing hyperpigmentation. Therefore, a detailed history of contact with allergens has to be elicited, and if found relevant, has to be confirmed by patch testing.

The story of a deformed leprous foot.

Eccrine syringofibroadenoma (ESFA) is a rare adnexal tumour of eccrine ductal proliferation. A 50 year old treated case of leprosy presented with a chronic non healing ulcer of 5 years duration on the deformity laden right foot. Multiple verrucous papules and plaques were seen surrounding the ulcer which showed histopathological findings consistent with ESFA. Although ESFA constitutes a rare association with leprosy, considering the load of treated cases in our country and elsewhere, it may represent an under-reported entity which requires more attention in the post elimination era.

Multiple Cutaneous Reticulohistiocytoma.

Multicentric reticulohistiocytosis is a rare non-Langerhans cell histiocytosis characterized in its full form by severe destructive arthritis, cutaneous nodules, and systemic manifestations. Cutaneous lesions may precede, accompany, or more commonly develop later than other features in this disease. We describe a case of multiple cutaneous reticulohistiocytoma without any systemic associations after thorough investigations.