Antituberculosis-Drugs Induced DRESS: A Multidrug Hypersensitivity or Drug Hypersensitivity Relapse? A Case Report

Area of Science:

• Pharmacovigilance
• Clinical Pharmacology
• Infectious Diseases

Background:

• Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) is a severe adverse drug reaction.
• Diagnosing DRESS in patients receiving multiple antituberculosis drugs (ATD) is challenging due to overlapping symptoms and long treatment durations.
• Identifying the specific culprit ATD is crucial to prevent treatment interruption and ensure favorable patient outcomes.

Observation:

• A 42-year-old female with multifocal tuberculosis developed DRESS symptoms (fever, edema, rash, eosinophilia, liver injury) 40 days after starting isoniazid, rifampicin, pyrazinamide, and ethambutol.
• Initial patch tests were negative. Reintroduction of ethambutol caused mild symptoms, but subsequent addition of isoniazid triggered a severe DRESS relapse.
• This pattern suggests a potential hypersensitivity relapse to ethambutol following an initial isoniazid-induced DRESS.

Findings:

• The patient presented with classic DRESS symptoms including hyperthermia, facial edema, cervical lymphadenopathy, generalized exanthema, eosinophilia, atypical lymphocytes, and liver injury.
• Sequential drug reintroduction revealed that while pyrazinamide and rifampicin were tolerated, ethambutol caused a mild reaction. However, a subsequent DRESS relapse occurred upon adding isoniazid.
• The findings indicate a complex hypersensitivity reaction, possibly a relapse triggered by ethambutol after an initial DRESS episode induced by isoniazid.

Implications:

• This case highlights the diagnostic complexity of DRESS in the context of multidrug antituberculosis therapy.
• It suggests that a drug initially suspected as the culprit may not be, and a subsequent drug could trigger a relapse or a new DRESS episode.
• Clinicians should consider sequential drug reintroduction cautiously and be vigilant for delayed or relapsing hypersensitivity reactions to antituberculosis drugs.