What are the causes of tinea manuum and tinea pedis?

The main causes of hand and foot癣 (tinea manuum and tinea pedis) include: 1. **Fungal infection**: Hand and foot癣 are primarily caused by infections with dermatophytes. Common pathogens include *Trichophyton rubrum* and *Trichophyton mentagrophytes*. 2. **Contact transmission**: Sharing personal items such as towels and slippers with individuals who have tinea, or coming into contact with infected animals, may lead to fungal infection. 3. **Autoinfection**: Fungal infections on the hands or feet may gradually spread to other areas of the body, causing tinea corporis (body ringworm) or tinea cruris (jock itch). 4. **Environmental factors**: Moist, hot, and poorly ventilated environments promote fungal growth and reproduction, increasing the risk of developing hand and foot癣. 5. **Weakened immune system**: Individuals with compromised immunity, such as those long-term users of antibiotics or corticosteroids, are more susceptible to fungal infections that may lead to hand and foot癣. 6. **Poor hygiene habits**: Poor hygiene practices, such as infrequent changing of shoes and socks or lack of handwashing, can facilitate fungal proliferation and transmission, increasing the risk of developing hand and foot癣.