Polymorphous light eruption. Patients with this condition develop papules, papulovesicles, or erythematous plaques in response to sun exposure. The lesions erupt a few hours to several days after the subject has been exposed to sunlight. Lesions are most often located on the face, upper chest, and exposed parts of the extremities. Ocular inflammation and cheilitis may also occur. Among North American and Latin American Indians, polymorphous light eruption tends to be a familial disease with childhood onset.
Nickel contact dermatitis. The development of an itchy eczematous eruption near the umbilicus is virtually pathognomonic for contact dermatitis to nickel. The source is the small metal snap in the blue jeans or the metal belt buckle. The simultaneous occurrence of an id reaction, sometimes with small lichenoid papules on the elbows and knees, is very common. Lesions can be treated effectively with topical corticosteroids, but the only cure results from strict avoidance of nickel. This is easier said than done. Parents must buy jeans without snaps or sew in a small piece of fabric to protect the underlying skin. Families should be reminded that wearing jeans with a metal snap for just several hours out of the month would reactivate the entire process. Children with contact dermatitis to nickel should also avoid metal jewelry and should be advised against ear piercing.