Urticarial dermatitis unresponsive to conventional treatment: a hidden sign of pancreatic cancer

Conflict of interest: the authors declare that they have no conflicts of interest. Urticarial dermatitis (UD) can present with various clinical features, including erythematous papules and plaques resembling urticaria and eczema‐like lesions that persist longer than 24 h.1 Histopathologically, UD has features of upper dermal perivascular lymphocytic inflammation with eosinophils, and no or minimal epidermal spongiosis.2 Spongiotic dermatitis can be seen as a paraneoplastic reaction in patients with adult‐onset recalcitrant eczema.3 We report a patient with UD unresponsive to conventional treatment that was associated with a hidden internal malignancy. A 66‐year‐old man presented with an 8‐month history with severe pruritus on his back. Physical examination revealed several erythematous weal‐like papules and urticaria‐like plaques on the back (Fig. 1a). Histological examination of a skin biopsy specimen identified a dermal hypersensitivity reaction (DHR) pattern with minimal epidermal spongiosis, and superficial infiltration of perivascular lymphocytes and interstitial eosinophils in the upper dermis (Fig. 2). Parakeratosis was absent.