Generalized pustular drug eruptions: confirmation by in vitro tests

Area of Science:

• Dermatology
• Immunology
• Pharmacology

Background:

• Generalized pustular eruptions are acute, aseptic pustular outbreaks in febrile patients, often linked to drug reactions.
• These eruptions are considered uncommon adverse drug reactions with limited confirmatory studies.
• Diagnosis typically relies on clinical presentation, histopathology, and exclusion of other causes.

Purpose of the Study:

• To describe a series of patients diagnosed with generalized pustular drug eruption.
• To confirm the etiological role of specific drugs using in vitro diagnostic tests.
• To evaluate the utility of macrophage migration inhibitory factor (MIF) and mast cell degranulation (MCD) tests.

Main Methods:

• Prospective study of clinical, pathological, and laboratory findings in six patients.
• In vitro MIF and MCD tests performed using drugs administered to patients.
• Analysis of dermatological manifestations, histopathology, and laboratory results.

Main Results:

• Dermatological findings included pustules, erythema, papules, and erythema multiforme-like lesions.
• Histopathology revealed subcorneal pustules, papillary edema, and inflammatory infiltrate with eosinophils in some cases.
• MCD tests were positive in all patients, and MIF tests in five of six, confirming drug causality. Ampicillin, Cefazolin, Tetracycline, Griseofulvin, and Enalapril Maleate were implicated drugs.

Conclusions:

• Diagnosis of pustular drug eruptions requires clinical, clinicopathological evidence, and exclusion of other conditions.
• In vitro MIF and MCD tests serve as valuable diagnostic tools for identifying causative drugs.
• Prompt drug withdrawal leads to rapid clinical improvement in affected patients.