Thirty percent of all adverse drug reactions are cutaneous adverse drug reactions (CADRs). About 2–3% of hospitalized patients can suffer CADRs from a wide variety of offending agents. A study investigated the clinical patterns, causative drugs and their association with autoimmune diseases in CADR patients. 

The study enrolled 174 CADR patients presenting to the dermatology OPD over 18 months. All were subjected to a detailed history, clinical examination, hematological, and biochemical investigations. Other investigations were done if indicated.

The observations of the study were as follows- 

• The mean age of the patients with cutaneous drug eruptions was found to be 40.2 years.
• 31.0% fell in the age group of 41–50 years.
• 53.4% were males and 46.5% were females.
• M: F ratio was 1.5:1. 

The maculopapular rash was the most common eruption noticed in 33.3% followed by fixed drug eruption in 17.2% and lichenoid dermatitis′ in 11.5%. 

Antimicrobials (39%) were the most common drugs responsible for CADRs with a fixed-dose combination of fluoroquinolones with nitroimidazoles. 

42 patients among 174 reported comorbidities like diabetes (15.5%), hypothyroidism (5.1%), rheumatoid arthritis (1.7%), vitiligo (1.1%), and SLE (0.5%). 

It was concluded that CADR patterns and the drugs causing various reactions are changing with time, possibly due to the introduction of newer molecules and changing trends in drug use. Additionally, CADRs with also been found to be significantly related to autoimmune diseases.

Source- Rana S, Gupta K, Agarwal N, Mqnsoon Ahamed AN. A Study of Cutaneous Adverse Drug Reactions and their Association with Autoimmune Diseases at a Tertiary Centre in South-West Rajasthan, India. Indian J Dermatol 2021;66:445