What causes hand fungus?

Tinea manuum, commonly known as "hand fungus," is referred to as "goose掌wind" in traditional Chinese medicine (TCM). It is a fungal skin infection occurring on the palmar surfaces of the fingers and hands, primarily caused by dermatophytes such as Trichophyton rubrum, Trichophyton mentagrophytes, or related fungi. It can be classified into the following types: 1. Vesiculopapular and squamous type: Begins on the palm, the palmar surface of the index finger, or ring finger, presenting with tiny pinhead-sized vesicles filled with clear fluid. After drying, these lesions desquamate and gradually expand to form annular or multiple ring-shaped lesions. 2. Hyperkeratotic and hypertrophic type: Often develops from the vesiculopapular-squamous type, characterized by diffuse redness, thickening of the palms, deepened skin lines, rough texture, and a tendency to fissure easily during winter. 3. Intertriginous (macerated) type: Less common, usually occurs after secondary bacterial infection of vesicles, presenting with acute or subacute eczematous changes. In treatment, TCM emphasizes principles of dispelling wind, eliminating dampness, clearing heat, and detoxifying, employing both internal medication and topical applications. Additionally, it is important to keep the hands dry and avoid prolonged contact with chemicals and solvents.