Penicillin / aminopenicillin allergy

Reaction signs & chairside management

• Angioedema / anaphylaxis risk on exposure

  IgE-mediated reactions can range from urticaria to angioedema (including orofacial/airway swelling) to anaphylaxis if a beta-lactam antibiotic is prescribed.

  Clinical management: Avoid penicillins and aminopenicillins (amoxicillin, ampicillin); select a non-beta-lactam alternative such as azithromycin, clindamycin, or doxycycline for dental infections/prophylaxis.

• Painful mouth and lip sores with peeling lining (Stevens-Johnson syndrome / toxic epidermal necrolysis)

  A rare but life-threatening delayed drug reaction in which the skin and mucous membranes blister and peel; the mouth and lips are involved in most cases, with widespread erosions, crusted bleeding lips and painful swallowing.

  Clinical management: Ask about any past severe rash with mouth sores or blistering, and treat that history as an absolute contraindication to the drug (record it clearly). A patient with new mouth/lip erosions plus fever, rash or eye irritation while on a recent antibiotic needs same-day medical referral. During recovery, keep oral care gentle: soft brush or sponge swabs, bland or chlorhexidine rinses, and lip emollient.