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.

Vitiligo in Children: A Birds Eye View.

Vitiligo in children is a distinct subset of vitiligo and differs from adult vitiligo. Characteristic features include family history of autoimmune or endocrine disease, higher incidence of segmental vitiligo, development of early or premature graying, increased incidence of autoantibodies and poor response to topical PUVA. The exact prevalence of vitiligo in children varies between 0.1-4% of the world population and seems to be higher in India than in other countries and it occurs more frequently in females. Around 12% to 35% of pediatric vitiligo patients have family members with the disease. The most common type of vitiligo in pediatric patients is vitiligo vulgaris, representing 78% of cases. The most commonly associated autoimmune disease is thyroiditis. Phototherapy and topical corticosteroids are the most commonly used treatments for adult vitiligo but are less useful in the pediatric population.

Systemic sclerosis: current concepts in pathogenesis and therapeutic aspects of dermatological manifestations.

Systemic sclerosis (SSc) is a chronic, multisystem connective tissue disease with protean clinical manifestations. Recent advances in understanding the pathogenic mechanisms have led to development of target-oriented and vasomodulatory drugs which play a pivotal role in treating various dermatological manifestations. An exhaustive literature search was done using Medline, Embase, and Cochrane library to review the recent concepts regarding pathogenesis and evidence-based treatment of salient dermatological manifestations. The concept of shared genetic risk factors for the development of autoimmune diseases is seen in SSc. It is divided into fibroproliferative and inflammatory groups based on genome-wide molecular profiling. Genetic, infectious, and environmental factors play a key role; vascular injury, fibrosis, and immune activation are the chief pathogenic factors. Vitamin D deficiency has been documented in SSc and correlates with the severity of skin involvement. Skin sclerosis, Raynaud's phenomenon (RP) with digital vasculopathies, pigmentation, calcinosis, and leg ulcers affect the patient's quality of life. Immunosuppressives, biologicals, and hematopoietic stem cell transplantation are efficacious in skin sclerosis. Endothelin A receptor antagonists, calcium-channel blockers, angiotensin receptor inhibitors, prostacyclin analogs, and phosphodiesterase type 5 (PDE-5) inhibitors are the mainstay in RP and digital vasculopathies. Pigmentation in SSc has been attributed to melanogenic potential of endothelin-1 (ET-1); the role of ET 1 antagonists and vitamin D analogs needs to be investigated. Sexual dysfunction in both male and female patients has been attributed to vasculopathy and fibrosis, wherein PDE-5 inhibitors are found to be useful. The future concepts of treating SSc may be based on the gene expression signature.

Keratoacanthoma centrifugum marginatum at an unusual site.

Keratoacanthoma (KA) is a rapidly evolving tumor, composed of keratinizing squamous cells originating in pilosebaceous follicles and resolving spontaneously if left untreated. It is relatively uncommon in dark-skinned and occurs in middle aged individuals. Males are three times more affected than females. It presents as firm, rounded, flesh-colored or reddish papule; with a rapid growth phase followed by spontaneous healing over three months. Two types of KA exist i.e., solitary and multiple. There are three rare clinical variants of solitary KA, namely giant KA, keratoacanthoma centrifugum marginatum (KCM) and subungual KA. In KCM, lesions are large, reaching upto 20cms. There is peripheral extension with raised, rolled border and atrophy in the center. There is no tendency toward spontaneous involution. The most common locations are dorsa of hands and legs, lesions on scalp being rare. A rare case of KCM occurring on scalp which is an unusual site is reported.

Blastomycosis-like pyoderma.

A 9-year-old female, presented with recurrent bilaterally symmetrically distributed flesh colored vegetative plaques, papules and nodules on trunk and upper and lower extremities since 15 days. Investigations revealed anemia, hypoproteinemia, decreased albumin and positive D-xylose test. Pus swab and biopsy for culture sensitivity showed Enterococci species. Biopsy showed spongiotic psoriasiform dermatitis with subcorneal pustule. She fulfilled criteria for the diagnosis of blastomycosis-like pyoderma viz. presentation of large verrucous plaques with pustules and elevated border, pseudoepitheliomatous hyperplasia with abscess histologically and growth of one pathogenic bacterium on culture or tissue biopsy. She responded to long-term amoxicillin-clavulanic acid therapy.