It is an acute and often life-threatening immunologic reaction, frequently heralded by scalp pruritus, diffuse erythema, urticaria, or angioedema. Bronchospasm, laryngealedema, hyperperistalsis, hypotension, and cardiac arrhythmia may occur. Antiobitics (especially penicillins), other drugs, and radiographic contrast agents are the most common causes of serious anaphylactic reactions. Hymenoptera stings are the next most frequent cause, followed by ingestion of crustaceans and other food allergens.
Prevention and Non-Pharmacological Treatment
If acute (existing for less than 3 months), exclude drug reactions (e.g. penicillin), or infection
Pharmacological Treatment
A: Chlorpheniramine (PO) 4–16 mg once at night for 7–10 days
OR
A: Promethazine (PO): Adults, 25–50 mg at night for 7–10 days
OR
A: Cetrizine (PO) 10mg once daily for 7–10 days
OR
C: Loratadine (PO) 10mg once daily for 7–10 days
Note: Warn about drowsiness. If no improvement after 1 month or the problem becomes chronic, refer to higher level facility for possible specialist care with combination therapy (H1, H2 inhibitors).
