Tinea capitis is a skin disease caused by a pathogenic cutaneous filamentous fungus on the hands and feet. It can be differentiated into tinea cruris and tinea pedis depending on the site of onset. Tinea versicolor is commonly known as tinea cruris and tinea pedis is commonly known as tinea pedis. The incidence of tinea pedis is much higher than that of ringworm, and it is particularly common in the south of China. The disease is mainly caused by the infection of Trichophyton rubrum, Trichophyton spp., Microsporum giganteum, and Trichophyton floccosum, of which Trichophyton rubrum accounts for more than 50%. In recent years, there has been an increasing trend of Candida albicans and other yeast infections. The disease is mainly transmitted by contact. Scratching the ringworm area with the hands or sharing shoes, socks, gloves, bath towels, or footbaths with the patient are the main ways of transmission. Tinea pedis is also an important source of infection for ringworm, ringworm of the hands, ringworm of the femur, and ringworm of the body. 2. Clinical manifestations Ringworm of the hands and feet (especially ringworm of the feet) is the most common superficial fungal disease, with a high incidence in summer and autumn, often manifesting as summer-heavy and winter-light or summer-onset and winter-healing. It mostly affects adults, and there is no significant difference in the proportion of men and women. The lesions tend to spread from one side of the limb to the opposite side. There are three types of tinea capitis: ① Blistering and scaling type: It occurs between the fingers (toes), the palm, the plantar area and the lateral edge of the foot. The lesions start out as deep blisters of pinpoint size, with clarified herpes, thick and shiny walls, and do not easily break down. After tearing away the wall of the blister, it reveals a honeycomb base and bright red vesicular surface with pronounced itching. The blisters dry up after a few days, showing collar-like or flaky flaking, and the lesions can continuously spread to the surrounding area. When the disease is stable, flaking is predominant. When the parasitic fungus is active, erythema and papules may occur on the basis of thickening of the lesions. At this time, there can be an itchy feeling. Hyperkeratosis: This type is characterized by the absence of blisters and pustules, local dryness, keratinous thickening of the lesions, rough and flaky surface, deepening of the texture, prone to cracking and bleeding, and the lesions can also spread to the dorsum of the foot. Generally no itching or mild itching. When there is cracking, pain. It is obvious in winter, and sometimes it does not recover in summer. Prevalent in the heel and palmoplantar area. (3) impregnated erosion type: in the warm and humid environment, the fungus long-term parasitic in between the toes, the ability to reproduce enhanced, easy to cause the epidermal keratin layer thickening, and due to moisture impregnation and whitening, sometimes often accompanied by sweating. This type of fungus is most common between the fingers (toes), especially between the 3rd to 4th and 4th to 5th fingers (toes). The skin is white with impregnation, the surface is soft and easy to peel, and reveals a red vesicular surface, or even fissures. There are varying degrees of itching and a foul odor when secondary to bacterial infection. The disease is often dominated by one type, or several types exist at the same time, and may shift from one type to another, such as blistering and scaling type in summer, and hyperkeratosis type in winter. Incomplete treatment is one of the main reasons for its persistence. Tinea pedis (especially the macerated type) is prone to secondary bacterial infections, pustules, ulcers, and even acute lymphangitis, lymphadenitis, cellulitis, or dermatitis. When the inflammatory reaction is obvious, it can also lead to ringworm rash. 3. Histopathology Lesions are located in the epidermis and superficial dermis. Common changes are spongy pustules or blisters in the epidermis and mixed inflammatory cell infiltration around the superficial dermal vessels, which can be acute, subacute or even chronic inflammatory changes. Acute phase: Mild hyperkeratosis with hyperkeratosis, intracellular and intercellular edema, and often spongy pustules in the upper sphenoid layer or microabscesses in the stratum corneum are seen. There is a mild to moderate infiltration of lymphocytes and neutrophils around the superficial dermal vessels, and papilledema. This is followed by the subacute phase: epidermal hyperplasia, hyperplasia and dilatation of the superficial dermal vessels, with a small number of eosinophils or plasma cells intermixed with the above-mentioned inflammatory cells. Chronic phase: marked hyperkeratosis, moderate sphenoid hypertrophy, dilated superficial dermal vessels, reduced inflammatory response, and a predominance of lymphocytes. Trichophyton verrucosum and Trichophyton rubrum can still involve the hair follicle, and the inflammatory reaction due to Trichophyton verrucosum is intense and can appear neutrophil aggregation, which is clinically manifested as clustered folliculitis type. 4.Diagnosis and differential diagnosis Based on the clinical manifestations of tinea capitis, combined with fungal microscopy or culture, a clear diagnosis can be made. The disease sometimes needs to be differentiated from eczema, sweat pimples, hyperhidrosis, palmoplantar pustulosis, etc. Palmoplantar pustulosis is a small, deep, sterile pustule on an erythematous plaque that dries up and desquamates after a few days and may fade on its own, with recurring episodes occurring symmetrically on the palm and metatarsal areas and rare involvement between the fingers (toes), with negative fungal microscopy. 5, prevention and treatment The key to prevention is to pay attention to personal, family and collective hygiene. Control the source of infection, should pay attention to timely and thorough treatment of superficial fungal disease; wear breathable shoes and socks, keep the foot dry; daily life, should also avoid acid and alkaline substances such as hand skin damage, do self-protection; do not share shoes and socks, bath tubs, foot basin and nail clippers and other household items, cut off the transmission pathway to avoid infection. Topical medication is the main treatment for this disease, and the key to successful treatment is to adhere to the medication, and the course of treatment usually takes 1~2 months; internal medication can be considered for tinea capitis with hyperkeratosis or if the topical medication is not effective. Different treatment methods should be chosen according to different clinical types: for example, for the blistering and scaling type, creams and aqueous agents that are less irritating (such as bifenazole cream or solution, etc.) should be chosen; for the impregnated erosion type, cold and wet compresses such as lead acetate solution and boric acid solution should be given, and when there is not much exudation, powders (such as kucca powder, miconazole powder, etc.) should be given, and after the lesions are dry, topical creams and aqueous agents should be used, and irritating and exfoliating drugs should not be used If you are a hyperkeratotic patient without chaps, you can use preparations with stronger exfoliating effects (such as compound benzoic acid ointment or tincture, etc.), and if you have chaps, you should use milder preparations (such as terbinafine ointment, etc.), and if necessary, you can use sealing package therapy. Internal medication Oral itraconazole (100 mg/d in a single dose for 15 days) or terbinafine (250 mg/d for 4 weeks) can be given. In the case of tinea pedis secondary to bacterial infection, the infection should be controlled with antibiotics followed by antifungal drugs; in the case of triggering ringworm rash, antiallergic drugs should be given along with active treatment of the active lesion.