Clinical Pattern and Causality Assessment of Drug-induced Cutaneous Reactions in a Tertiary Care Hospital in India: A Prospective Study

Background: Cutaneous Adverse Drug Reactions (ADRs) are common and pose a serious challenge to physicians, especially in cases when the patient has many comorbidities, is polypharmacy, or self-administers over-the-counter medications.

Objective: The objective of this study is to analyze the clinical pattern and incidence of cutaneous ADRs and perform causality assessment using the WHO-UMC scale and Naranjo's scale. The severity of the reactions was determined by the Hartwig scale.

Methods: This was conducted as a prospective observational study in patients admitted to SRM Medical College, Kattankulathur, Tamil Nadu, India, between November 2016 to August 2018 after obtaining Institutional Ethics Committee clearance of all adverse drug reactions reported at the hospital.

Results: Of the 158 ADRs reported during the time period, 101 were cutaneous ADRs, of which the most common presentation was maculopapular rash (n=42; 41.58%). The most common drugs which produced cutaneous adverse reactions were antimicrobials (n=58; 57.42%) followed by NSAIDs (n=35; 34.6%). The causality assessment as per the Naranjo scale yielded 3.96% (4) cases as definite, 81.18% (82) as probable, and 14.85% (15) as possible, whereas the WHO scale yielded 9 (89.10%) certain, 64 (63.36%) probable and 28 (27.72%) possible cases. The severity of the cases determined as per the Hartwig scale yielded 82.17% cases as mild and 17.82% as moderate.

Conclusion: It is important to recognise the ADRs at the right time and exert caution in future use. This can minimise harm to the patient both physically and financially and improve the outcome of the treatment.