Dermatology Drug Eruptions and Leprosy for UPSC CMS: Patterns, Types and Clinical Recognition

Drug Eruptions#

Morbilliform: Most common. Symmetric maculopapular rash. Starts on trunk, spreads.

Fixed drug eruption: Round erythematous plaque, recurs at same site. Lips, genitalia common. Darker pigmentation after healing.

Stevens-Johnson Syndrome (SJS): Targetoid lesions, mucous membrane involvement, fever. <10% BSA involved. Mortality 1-5%.

Toxic Epidermal Necrolysis (TEN): >30% BSA detachment. Mucosal involvement. Mortality 30-50%.

Leprosy#

Classification (Ridley-Jopling):

• TT (Tuberculoid): 1-2 hypopigmented macules, strong +ve Lepromin
• BT (Borderline tuberculoid): 3-10 lesions
• BB (Mid-borderline): Variable
• BL (Borderline lepromatous): Many lesions, +ve Lepromin
• LL (Lepromatous): Diffuse, leonine facies, -ve Lepromin