Urticaria

– Papules: transient, erythematous, oedematous, pruritic, resembling nettle stings.
– Look for a cause: food or drug (particularly antibiotic) allergy, insect bites; the invasive stage of a bacterial or parasitic infection (ascariasis, strongylodiasis, ancylostomiasis, schistosomiasis, loiasis), viral infection (hepatitis B or C); generalised disease (cancer, lupus, dysthyroidism, vasculitis).

Treatment

– If the pruritus is intense, antihistamines for a few days:
loratadine PO
Children over 2 years and under 30 kg: 5 mg (5 ml) once daily
Children over 30 kg and adults: 10 mg (1 tab) once daily
or
chlorphenamine PO
Children 1 to < 2 years: 1 mg 2 times daily
Children 2 to < 6 years: 1 mg 4 to 6 times daily (max. 6 mg daily)
Children 6 to < 12 years: 2 mg 4 to 6 times daily (max. 12 mg daily)
Children over ≥ 12 years and adults: 4 mg 4 to 6 times daily (max. 24 mg daily; 12 mg daily in elderly patients)
or
promethazine PO
Adults: 25 mg once daily at bedtime

– In the event of anaphylactic reaction, see Shock (Chapter 1).