A 28-year-old woman presents with a solitary, well-demarcated, erythematous patch with central clearing on the inner thigh. Wood's lamp examination shows no fluorescence, and KOH mount is positive for dermatophytes. Regarding tinea cruris, all of the following statements are correct EXCEPT:

Explanation

## Tinea Cruris: Clinical Features and Epidemiology ### Definition and Presentation **Key Point:** Tinea cruris is a dermatophyte infection of the groin and inner thigh region, characterized by a well-demarcated, erythematous patch with a raised, scaling border and often central clearing. ### Sparing of Genital Structures **High-Yield:** Tinea cruris classically spares the scrotum and labia majora. This is a distinguishing feature from other conditions like candidiasis (which involves the scrotum and labia). The reason is the acidic pH and the presence of sebaceous glands in these areas, which are unfavorable for dermatophyte growth — this statement is TRUE. ### Clinical Morphology | Feature | Characteristic | |---------|----------------| | Border | Sharply demarcated, raised, scaling | | Center | Often clear or hypopigmented | | Distribution | Bilateral, symmetric involvement of groin and inner thighs | | Color | Erythematous to brown | **Clinical Pearl:** The well-demarcated border with central clearing is a hallmark of tinea cruris and helps differentiate it from other groin dermatoses — this is TRUE. ### Gender Predilection: The Critical Error **Key Point:** Tinea cruris is MORE COMMON IN MALES than females. This is contrary to the statement in option 3. Males have higher rates of tinea cruris because of: - Greater surface area of skin folds in the groin - Higher sweat production and moisture in the groin region - Occlusion from tight clothing and athletic activities - Higher prevalence of other tinea infections (tinea pedis, tinea corporis) that can spread to the groin Females are actually more commonly affected by candida vulvovaginitis, not tinea cruris. ### Complications and Risk Factors **Clinical Pearl:** Secondary bacterial infection and maceration can occur, especially in obese patients, those with poor hygiene, or those with excessive sweating. This is a recognized complication — this statement is TRUE. ### Why Option 3 Is Incorrect The statement claims tinea cruris is more common in females, which is factually incorrect. Tinea cruris has a male predominance, making this the exception. [cite:Fitzpatrick's Dermatology in General Medicine 9e Ch 133]