What are the causes of tinea manuum and tinea pedis?

Tinea manuum and tinea pedis are common dermatological conditions with complex and varied causes. The main causes are as follows: 1. **Fungal infection**: Tinea manuum and tinea pedis are primarily caused by infections with dermatophytes, including Trichophyton, Microsporum, and Epidermophyton species. Among these, Trichophyton rubrum and Trichophyton interdigitale are the most common. 2. **Environmental factors**: Prolonged exposure to moist, hot environments, wearing non-breathable shoes and socks, and excessive sweating all promote fungal growth and reproduction, thereby increasing the risk of developing tinea manuum or tinea pedis. 3. **Individual factors**: Reduced immunity, poor personal hygiene, and skin damage can also predispose individuals to tinea manuum and tinea pedis. Individuals with weakened immune systems, such as patients with diabetes or those on long-term antibiotic or immunosuppressive therapy, have decreased resistance to fungal infections and are more susceptible to infection. 4. **Genetic factors**: The occurrence of tinea manuum and tinea pedis may also be related to genetic factors. Individuals with a family history of these conditions have a higher risk of developing them. It is recommended to maintain good personal hygiene, avoid prolonged exposure to damp environments, wear breathable and comfortable shoes and socks, and strengthen one's immune system.