D2.394 - Mycoplasma-Induced Drug Hypersensitivity: Rare Complication or Coincidence?

Background

Mycoplasma-induced rash and mucositis (MIRM) is a rare complication of Mycoplasma pneumoniae infection and is often a diagnostic challenge, particularly in distinguishing it from Stevens–Johnson syndrome (SJS). While SJS is most often drug-induced, infections—particularly herpesvirus infections—have also been reported as triggers; however, to our knowledge, it has not been reported in the context of Mycoplasma infection.

Method

We collected clinical data and laboratory results from the patient’s medical records. Written informed consent was obtained from the patient.

Results

A 34-year-old previously healthy woman with no atopic history presented with bilateral eye irritation and was prescribed levofloxacin eye drops for presumed conjunctivitis. On the same day, she also developed fever, rhinorrhea, and nasal congestion before using the eye drops. After four doses over 24 hours of the eye drops, she developed worsening conjunctivitis, blepharitis, and erythematous patches with atypical target lesions on the face and trunk. The eye drops were discontinued because SJS could not be excluded, and she was referred to our hospital. Allergist, Dermatologist, Ophthalmologist, and Infectious diseases were consulted. Mucosal erosions involving the oral cavity, eyelids, and genitalia were more prominent than the skin lesions, which involved 10% of the body surface area. The differential diagnosis included MIRM versus levofloxacin-induced SJS. Skin biopsy showed full-thickness epidermal necrosis with non-specific direct immunofluorescence findings, which did not distinguish between MIRM and SJS. Subsequent serology demonstrated seroconversion of Mycoplasma pneumoniae antibodies after an initially negative result, supporting MIRM as the final diagnosis. She was treated with azithromycin, systemic and topical corticosteroids, and supportive care, with complete resolution within 40 days. For drug allergy evaluation, the patient declined levofloxacin skin test and drug provocation test. Lymphocyte transformation test was positive (stimulation index of 2.3), providing additional evidence supporting levofloxacin hypersensitivity.

Conclusions

This is the first case report describing the coexistence of MIRM and levofloxacin-induced SJS. We hypothesize that primary Mycoplasma pneumoniae infection might increase susceptibility to drug exposure during this period. However, a coincidental occurrence of these two conditions, without any causal association, may also be possible.