New emerging diseases or syndromes in dermatopathology with impact on clinical management

New cutaneous emerging disorders have been recently defined, in terms of both clinical and histopathological features, with impact on clinical management. Aquagenic palmoplantar keratoderma is a hyperwrinkling of palms and/or soles on exposure to water, which may be a sign of cystic fibrosis or of the carrier status of this disease. Pretibial mucinosis is not only associated with Graves' disease (pretibial myxedema), but can be a consequence of lower leg edema. In particular, it has been observed in obese patients with lymphedema and in venous insufficiency. Circumscribed palmoplantar hypokeratosis should not be underestimated because it might have a potential of malignant transformation. An extensive skin erythematous patch of the chest, with mucinous angiomatosis at the histopathological examination, is an early sign of an underlying plasmacytoma (adenopathy and extensive skin patch overlying a plasmacytoma syndrome). Eosinophilic annular erythema is a clinical subset of Well's syndrome presenting with an annular or figurate pattern.