A 26-year-old man presents with multiple small, ill-defined, non-scarring patches of hair loss scattered over the temporal and occipital scalp, described as moth eaten. There is no scaling or erythema. Serological testing should be directed towards detecting:

• A Anti-transglutaminase antibodies
• B Treponemal antibodies ✓
• C Thyroid peroxidase antibodies
• D Anti-Ro and anti-La antibodies

Explanation

Moth-eaten alopecia, a random patchy loss of hairs without inflammation or scale, is a classic cutaneous sign of secondary syphilis and warrants treponemal serology along with palmoplantar and mucosal examination. Alopecia areata gives well-defined round patches with exclamation mark hairs rather than a diffuse moth-eaten pattern. Anti-Ro and anti-La relate to neonatal lupus and subacute cutaneous lupus, which cause scarring scalp lesions instead.

Reference: Rook's Textbook of Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.