Calcipotriol, a first-line topical agent in plaque psoriasis, exerts its therapeutic effect through which mechanism?

• A Blocking the IL-17 receptor on keratinocytes
• B Inhibiting phosphodiesterase 4 and increasing intracellular cAMP
• C Binding the vitamin D3 receptor to inhibit keratinocyte proliferation and promote differentiation ✓
• D Inhibiting leukotriene B4 mediated neutrophil chemotaxis

Explanation

Calcipotriol is a synthetic vitamin D3 analogue that binds the nuclear vitamin D receptor, suppressing keratinocyte proliferation and enhancing terminal differentiation, correcting the abnormal epidermal turnover of psoriasis. Doses above roughly 100 g per week can cause hypercalcaemia, so total weekly application is limited. Apremilast is the PDE4 inhibitor and IL-17 blockade is achieved systemically by biologics, not topicals.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.