differential diagnosis
Last reviewed 01/2018
Erythropoietic porphyria must be differentiated from other types of photosensitivity, and from contact dermatitis and angioneurotic oedema.
- polymorphous light eruption - but the lesions are characteristically papules and plaques, and a family history of photosensitivity is uncommon
- idiopathic solar urticaria - but not associated with elevated protoporphyria in red blood cells and faeces
- contact dermatitis - may involve non-light exposed areas such as skin folds, submental area
- angioneurotic oedema - but lesions may occur anywhere on the body