Ruxolitinib Cream Guide: Topical JAK Inhibitor for Atopic Dermatitis and Vitiligo

　　1.Overview and Indications

　　Ruxolitinib Cream(generic:ruxolitinib,brand:Opzelura)is a topical Janus kinase(JAK)inhibitor.It is indicated for short-term,non-continuous treatment of mild to moderate atopic dermatitis in immunocompetent adults and children aged 2 years and older,and for topical treatment of non-segmental vitiligo in adults and adolescents aged 12 years and older.

　　2.Application and Maximum Usage

　　There is no"starting"or"maintenance"dose escalation;usage is based on application area and frequency.

　　Atopic Dermatitis(AD):Apply a thin layer to affected areas twice daily(BID).Total treated area must not exceed 20%of body surface area(BSA).Discontinue when signs and symptoms resolve.If no improvement after 8 weeks,re-evaluate.

　　Vitiligo:Apply BID to depigmented areas,not exceeding 10%BSA.Treatment typically requires at least 24 weeks for satisfactory results.

　　Maximum usage limits:Adults and children≥12 years:max 60 g per week(or 100 g per 2 weeks).Children 2–11 years:max 60 g per 2 weeks.These limits are safety caps,not titration targets.

　　3.Local Precautions and Contraindications

　　As a topical agent,there are no oral dietary restrictions,but the following must be observed:

　　Not recommended with biologics,other JAK inhibitors,or potent immunosuppressants(e.g.,azathioprine,cyclosporine).

　　Avoid eyes,mouth,nasal mucosa,and broken skin.

　　Wash hands after application(unless hands are the treatment site).

　　Do not apply other topical products simultaneously unless directed by a physician.

　　No food interactions since it is not oral.

　　4.Differences Between AD and Vitiligo Use

　　Age:AD from 2 years;vitiligo from 12 years.

　　BSA limit:AD≤20%;vitiligo≤10%.

　　Duration:AD is short-term,stop when clear;vitiligo requires long-term use(≥24 weeks).

　　Condition:AD is inflammatory;vitiligo is pigment loss.

　　5.Side Effects and Safety

　　Common local reactions include burning,stinging,and dryness(5–10%),usually mild to moderate.Prolonged large-area use may cause minimal systemic absorption,but levels are far below those of oral JAK inhibitors,with no reported systemic JAK-related adverse effects.Use cautiously in pregnancy and lactation.

　　6.Efficacy Expectations

　　AD:~50–60%of patients achieve IGA 0/1(clear or almost clear)within 8 weeks.

　　Vitiligo:~30–40%show≥50%improvement in facial vitiligo area scoring index at 24 weeks.

　　Patience is required;rapid results should not be expected.