Granulomatous skin involvement in a patient with an unusual NOD2 mutation.

Blau syndrome is a rare disorder that is classically characterised by granulomatous arthritis, skin eruptions and uveitis, which occur in the absence of lung involvement. Blau syndrome has been linked to encoding mutations in the NOD-2 gene and is inherited in an autosomal dominant form. The most commonly observed mutations are missense substitutions affecting the arginine residue at position 334. The rare E600A mutation has been described as causing uveitis without skin involvement. Our patient is a 54-year-old man with an unusual heterozygous c.1799A>C(E600A) mutation, who was seen for bilateral lower extremity swelling and pain. On physical examination, he was found to have lower leg oedema with decreased hair growth on the affected area. Biopsy showed non-caseating micro-granulomas consistent with a diagnosis of Blau syndrome. The patient had excellent response to colchicine, but this was stopped because he developed elevated transaminases. Thus, we present an unusual genetic form of a rare condition and we demonstrate skin involvement in a subtype where cutaneous involvement has not hitherto been reported. In addition, the type and presentation of the skin involvement is different from that normally found in classic Blau syndrome. Finally, we report his response to colchicine, although it was ultimately not tolerated by this patient.

Dermatopathologic manifestations of intravenous drug use.

BACKGROUND: The rate of intravenous drug use (IVDU) has been increasing nationally; however, cutaneous manifestations of IVDU have infrequently been investigated. We report a series of the clinicopathological correlation of IVDU in the skin. METHODS: A search of surgical pathology files between the years 2000 and 2014 was performed for cutaneous specimens from patients with a reported history of IVDU for which the histopathological findings could not be attributed to another etiology. Ten cases for which slides were available were included in the study. RESULTS: Patients had an average age of 39.7 years and had active or recent history of IVDU. Clinical impressions included ulcer, granulomatous dermatitis, vasculitis, pyoderma gangrenosum and hyperpigmentation at injection sites. Histopathology revealed leukocytoclastic vasculitis (n = 2), dermal pigment deposition (n = 3), non-specific ulceration/scarring (n = 4) and necrobiosis lipoidica-like dermatitis (n = 1). No infectious etiology or polarizable foreign material was identified in any case. CONCLUSIONS: Cutaneous manifestations of IVDU should be considered in the differential as an etiology for dermatopathologic findings in high-risk patients. We report histopathological findings beyond the scope of those most commonly associated with IVDU. We aim to raise awareness of the cutaneous manifestations of IVDU to improve clinicopathological correlation and patient management in light of the ongoing epidemic.