Papular urticaria. Clusters of red papules surrounded by an urticarial flare due to cat fleas.
Papular urticaria. Characteristic red papule with central puncta.
Papular urticaria. Giant red flare following insect exposure.
Venomous spider bite. Central necrosis and indurated red border in brown recluse spider bite.
CLINICAL FEATURES
Intensely itchy clustered red papules, some with an urticarial flare, are the most common form of insect bite reactions. A tiny central punctum is present. Children 18 months to 7 years are susceptible as they are hypersensitive, but older children and adults similarly exposed are not. Typically, the recurrent crops lasting 2 to 10 days first develop in the spring and summer and last 3 to 9 months.
TREATMENT
The use of insect repellant such as bite blocker or 6% DEET to make the child less attractive to the insect will help.
Prophylactic use of an oral antihistamine such as cetirizine once daily, and a moderate-strength topical steroid twice daily will relieve symptoms.
Venomous brown recluse spider bites require prompt intervention with oral prednisone 2 mg/kg/day for 5 days. In some, surgical excision of the bite site to remove the venom is helpful, and toxic children require hospitalization with fluid and electrolyte support.
Widow spider bites may be improved with widow antisera administered within hours of the bite.
