Identification of Helicobacter pylori in skin biopsy of prurigo pigmentosa.

A 23-year-old Chinese man presented with a 3-year history of a pruritic eruption. On examination, pink urticarial papules associated with hyperpigmented reticulated patches were noted on his neck, back, and upper chest. Histopathology revealed vacuolar interface dermatitis and numerous gram-negative rods within a dilated hair follicle. The organisms were reactive with anti-Helicobacter pylori immunohistochemisty. The histologic findings and clinical presentation support the diagnosis of prurigo pigmentosa. Additional testing demonstrated a positive urease breath test and serum H. pylori IgG antibodies. The patient was referred to gastroenterology and treated with appropriate antibiotics. After treatment, esophagogastroduodenoscopy revealed chronic gastritis without evidence of H. pylori infection and his skin showed reticulated hyperpigmented patches without evidence of active inflammatory papules. Although previous reports have associated prurigo pigmentosa to H. Pylori gastritis, this is the first report of H. pylori organisms identified in a skin biopsy of prurigo pigmentosa.