Itchy skin disease

Urticaria diagnostic challenge

Diagnostic challenge: one of the following patients has urticaria. Which one?

* || Papular urticaria or widespread insect bites. There are clustered urticated plaques, some with a central punctum or excoriation. A row of three is particularly suggestive of fleabites. *! || Typical urticarial weals, in a patient with chronic idiopathic urticaria. * || Annular erythema. Sometimes confused with urticaria, because the size and position of the plaques may slowly shift. However there is usually a fine scale on the inner aspect of the rim. * || Erythema multiforme. The erythematous plaques are characteristically target-shaped and often have a central vesicle or bulla. The majority of lesions are found on the distal limbs