ANSWER 65
The diagnosis is acute drug hypersensitivity causing severe erythema multiforme
(Stevens–Johnson) syndrome. The pointers to this diagnosis are the rapidity of onset and
its timing related to starting the penicillin, antibiotics being the commonest group of drugs
causing this syndrome, and the form and distribution of the lesions. The chest X-ray shown
is normal.
!
- Streptococcal (presumed) infection spreading to the soft tissues; this is much less
common in young healthy patients compared to the elderly; its distribution would
be diffuse rather than discrete lesions, and was excluded by negative culture of the
lesions. - Acute leukaemia or neutropenia can present with mucosal ulceration, but not
these skin lesions, and these diagnoses are excluded by the blood count and film.
Differential diagnoses of the rashDrugs other than penicillin should be considered as a cause, e.g. analgesics for the orig-
inal painful throat. The patient had taken a few doses of paracetamol, leaving the penicillin
as the likeliest candidate by far as the cause.
Management consists of:- stoppingthe penicillin and substituting an alternative antibiotic if required: cultures
were negative in this case at this stage - a short course of steroids, e.g. 30 mg prednisolone daily for 5 days to reduce the
inflammation - observe for secondary infection of the ulcers
- analgesia
- warn the patient not to take penicillin or related drugs in the future
- record the penicillin allergy clearly in GP and hospital notes.
! Management
- A drug history is an essential part of every patient’s history.
- Always consider drugs as a cause of complications during a patient’s illness.
- Drug allergies should be recorded prominently in medical notes.