A 35-year-old woman from Delhi presents with a 2-month history of scaling and erythema on the dorsal surfaces of both hands and fingers, with sparing of the palms. She works as a housewife with frequent hand washing and exposure to water. The lesions are mildly pruritic and have not responded to topical steroids. KOH preparation shows branching septate hyphae. Which is the most likely diagnosis?

## Diagnosis: Tinea Manuum **Key Point:** Tinea manuum is a dermatophyte infection of the hands, classically affecting the dorsal surfaces and interdigital spaces while sparing the palms. It is more common in women and is exacerbated by frequent water exposure. ### Clinical Features of Tinea Manuum | Feature | Details | |---------|----------| | **Site** | Dorsal hands, fingers, interdigital spaces; palms typically spared | | **Appearance** | Scaly, erythematous patches; may have raised borders | | **Symptoms** | Mild to moderate pruritus; may be asymptomatic | | **Risk factors** | Female > male; frequent hand washing; water exposure; poor drying | | **Causative agents** | *Trichophyton rubrum* (most common), *T. mentagrophytes* | | **KOH mount** | Branching septate hyphae | | **Response to steroids** | Poor or worsening (steroids may enhance fungal growth) | **High-Yield:** Tinea manuum is a site-specific variant that predominantly affects women due to occupational exposure (housework, frequent hand washing) and is characterized by dorsal hand involvement with palm sparing — a key distinguishing feature. ### Differential Diagnosis | Condition | Key Distinguishing Feature | |-----------|---------------------------| | **Tinea corporis** | Affects trunk, limbs, face; not site-specific to hands; would show similar hyphae but different anatomical distribution | | **Contact dermatitis** | History of allergen exposure; no hyphae on KOH; responds to topical steroids (unlike tinea); often has vesicles or oozing | | **Dyshidrotic eczema** | Presents with vesicles and pustules on palms and lateral fingers; no hyphae on KOH; responds to topical steroids; typically bilateral and symmetric | **Clinical Pearl:** The combination of dorsal hand involvement, palm sparing, female gender, water exposure, and failure to respond to topical steroids is highly suggestive of tinea manuum. Fungal infection often worsens with steroid use due to immunosuppression. **Mnemonic:** **MANUUM** — **M**ale-sparing (female predominant), **A**ffects dorsal surface, **N**ot palms, **U**nder water exposure, **U**nresponsive to steroids, **M**anifests as scaly erythema. ### Management - Topical azoles (miconazole, clotrimazole, terbinafine cream) for 4–6 weeks - Systemic terbinafine (250 mg daily for 4–6 weeks) if extensive or unresponsive - Hygiene: keep hands dry, avoid prolonged water exposure, use antifungal powder - Avoid occlusive gloves; use cotton gloves if necessary