Cutaneous manifestations of Churg-Strauss syndrome: report of two cases and review of the literature

Churg-Strauss syndrome (CSS) is a small-vessel vasculitis characterized by severe asthma, lung/tissues infiltrates, extravascular necrotizing granulomas, and eosinophilia. Cutaneous involvement is common but may not be highly suggestive. Two typical cases of CSS with cutaneous involvement are herein reported, both females, 37 and 54 years old, presenting with lower limbs palpable purpura and urticarial lesions of the neck, respectively. A comprehensive review of the literature showed that cutaneous manifestations occurred in 40-81% of CSS patients and were the presenting sign in 14% of the patients. Moreover, a total of 68 cases of CSS with a detailed description of the cutaneous lesions have been published. In the majority of these patients, skin lesions allowed for the histopathological diagnosis of CSS. The most common clinical features were papulo-nodules with the histological picture of extravascular Churg-Strauss granuloma followed by purpuric and/or necrotic lesions in the lower limbs corresponding to small-vessel vasculitis with eosinophils. Less common lesions included urticarial lesions and livedo reticularis. Therefore, a high index of suspicion on skin lesions and the proper lesion selection for histological examination may be very important for early diagnosis of CSS. Clinical-pathological correlation is essential, as both clinical and histological features are not pathognomonic.