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Sensitization to penicillin associated with infectious mononucleosis

In vivo skin tests indicated sensitization to penicillin may develop within infectious mononucleosis, according to recent study results in Allergy, Asthma & Clinical Immunology.

Researchers studied 10 patients (median age, 22.9 years) who were treated for infectious mononucleosis between 2002 and 2012 at the University of Szeged in Hungary. The patients were analyzed for sensitization to antibiotics. Each patient was given antibiotic therapy, using amoxicillin/clavulanic acid, before the emergence of skin lesions.

Researchers used the lymphocyte transformation test (LTT) almost 2 months after skin eruptions ended to determine T-cell proliferation as an indicator of drug sensitization.

In vivo cutaneous tests using penicillin then were conducted in patients with negative LTT results to amoxicillin.

Six of the 10 patients with suspected sensitization to amoxicillin and negative LTT results were further investigated in vivo by skin prick, intradermal and patch testing. All showed negative responses with skin prick tests, while the intradermal tests resulted in positive results in four patients.

“Our data demonstrate that in vitro testing is not sensitive enough in determining drug sensitization for penicillin in patients who develop skin symptoms during mononucleosis infection,” the researchers wrote. “In vivo tests should be performed to detect sensitization and indeed with skin tests our results confirmed that sensitization to penicillin may develop within infectious mononucleosis.”

Disclosure: The researchers report no relevant financial disclosures.