Cephalosporin induced toxic epidermal necrolysis and subsequent penicillin drug exanthem.
BACKGROUND
Drug hypersensitivity is classically divided into IgE mediated and non-IgE mediated disease. We report a rare case of consequent IgE mediated and non-IgE mediated reactions within the beta lactam class of antibiotics.


METHODS
An 84-year-old man developed toxic epidermal necrolysis (TEN) due to ceftriaxone, a third generation cephalosporin, involving 72% of the body surface area. The patient recovered but within weeks subsequently developed an acute IgE mediated allergic reaction to piperacillin/tazobactam, an extended spectrum penicillin. Further IgE RAST revealed positive results to penicillin major determinant.


CONCLUSIONS
This case demonstrates the complexity of drug hypersensitivity reactions. While it is accepted that IgE mediated penicillin allergy is a predisposition to cephalosporin allergy, this case displays an unusual correlation between drug hypersensitivity and drug class. There have been few studies that evaluate the cross reactivity with penicillin or other beta-lactams in subjects with primary hypersensitivity to cephalosporins. This clinical scenario emphasizes the need of more studies on cephalosporin allergy in particular as shown by this case of sequential non-IgE mediated cephalosporin induced TEN reaction pursuant by an IgE mediated penicillin allergy.
UCLA West Los Angeles VA Medical Center 90073, USA. aslam@ucsd.edu
Amanda
A
Lam
Inderpal
I
Randhawa
William
W
Klaustermeyer
D000369:Aged, 80 and over; D002511:Cephalosporins / Q000276:immunology*; D004342:Drug Hypersensitivity / Q000209:etiology*; D005076:Exanthema / Q000209:etiology; D006801:Humans; D008297:Male; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000276:immunology; D010878:Piperacillin / Q000276:immunology; D000077725:Piperacillin, Tazobactam Drug Combination; D013262:Stevens-Johnson Syndrome / Q000209:etiology*
D002511:Cephalosporins; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D010878:Piperacillin