Juvenile spring eruption
This occurs most commonly in boys between the ages of five and 14. Symptoms usually develop 24 hours after exposure to ultraviolet light. It is less common in girls because their ears tend to be better protected from the sun by their hair. An itchy rash can occur in the early spring in some cases.
Small blisters develop on the rim of the ear lobe. These crust and heal within a week, with little scarring. Some cases develop enlarged cervical lymph nodes. The underlying cause of this allergy to the sun is unknown but it is thought to be a localised form of polymorphic light eruption, which affects wider areas of sun exposed skin.
Recurrences can follow further exposure to the sun but the skin gradually becomes 'hardened' to light over time. Investigations are unnecessary, as the diagnosis is a clinical one.
Management involves protection from the sun with sunscreen and hats. A potent topical corticosteroid and emollient can also ease symptoms.
Read more Common skin problems in primary and community care
Cutaneous (keratin) horn