Onychomycosis

　　Gray nail is often caused by Trichophyton rubrum, Trichophyton sorediosum, and Trichophyton mentagrophytes, among others. Other fungi such as Trichophyton schoenleinii, Trichophyton violaceum, Trichophyton terrestre, Trichophyton rubrum, and Trichophyton concentricum can also cause onychomycosis. Fungal leukonychia is often caused by Trichophyton sorediosum, and occasionally it can also be caused by head and saw fungi, and Trichoderma viride.

　　Healthy nails are not easily infected, and the tendency to infect fungal nails may be related to genetics, diabetes, local arterial and venous circulation, and lymphatic reflux disorders, as well as peripheral neuropathic diseases. Nails on the fingers and toes that are frequently exposed to damp environments and injuries are easily infected by fungi. Tinea pedis is the direct cause of most toe nail fungal infections, while nail fungal infections may be spread from tinea manuum or from frequent scratching of the feet, and nail fungal infections are more common on the toes than on the fingers. The pathogens of onychomycosis include dermatophytes, yeasts, and molds, with Trichophyton rubrum, Trichophyton tonsurans, and Trichophyton mentagrophytes being the most common dermatophytes. It is possible for the same nail to be infected by two types of dermatophytes, two dermatophytes plus one yeast (including Malassezia), or dermatophytes plus yeasts and molds.

　　Gray nail is often caused by other filamentous fungi, yeast-like fungi, and yeasts, and is mostly seen in malnourished nails. It has been confirmed that Candida albicans and Trichophyton mentagrophytes can cause onychomycosis, and in recent years, it has been found that Candida glabrata and other fungi can also often cause onychomycosis.

　　Severe gray nail can cause pain and discomfort, and the muscles inside the affected nail may be exposed or compressed by thickened nails. Once subjected to various injuries, bacteria can easily penetrate, thus triggering complications such as paronychia, onychia, and finger abscess, leading to severe systemic diseases such as erysipelas or cellulitis. The specific conditions are as follows:

　　1: Onychia It is an inflammatory reaction involving the skin folds around the nail, characterized by acute or chronic suppurative, tender, and painful swelling of the perionychial tissue, caused by paronychia abscesses. When the infection becomes chronic, transverse ridges appear at the base of the nail, and new ridges appear with recurrence.

　　2: Paronychia It is usually caused by bacterial infection, with staphylococci and streptococci being the most common. The symptoms include acute redness and swelling, along with pus blisters, which mostly appear around the nail bed. Most patients will feel pain.

　　3: Finger abscess It is a common skin infection caused by streptococci and staphylococci.

　　The nails of the fingers or toes turn grayish-white, which is commonly referred to as 'gray nail', and is known as onychomycosis in modern medicine. It is a chronic infectious nail disease caused by dermatophytes, yeasts, and molds that invade the nail plate and the nail bed underneath. Onychomycosis is a common and frequently occurring disease in dermatology, and it is also a disease that is relatively troublesome to treat. The common symptoms of gray nail include the following:

　　1: The most common pathogenic bacteria causing onychomycosis are Trichophyton rubrum.

　　2: Irregular nail surface: Keratin accumulation under the nail plate leads to the destruction of the nail plate.

　　3: Nail plate lifting: Keratin under the nail plate falls off, and the nail plate is only connected to the nail bed at the root.

　　4: Thickening: Keratin accumulation under the nail plate.

　　5: Turbidity: The nail plate is not transparent, appearing cloudy or stained, losing its luster.

　　6: Nail plate shedding: The nail plate is completely destroyed, with only a small amount remaining on the nail bed.

　　7: Color change: The affected nails may appear white, yellow, gray, brown, or even black.

　　Onychomycosis is a difficult-to-treat chronic infectious disease. To prevent the occurrence of onychomycosis, it is necessary to take positive and effective preventive measures to prevent the infection of nails by pathogenic fungi. The main points are as follows:

　　1: Keep the living environment clean, do not create an external environment for the growth and reproduction of pathogenic fungi, such as avoiding crowded housing, dampness, paying attention to indoor ventilation and air exchange, regularly drying bedding, and washing sheets and underwear. The daily necessities of onychomycosis and tinea pedis patients in the family should be disinfected regularly with boiling water, and items that cannot be scalded should be disinfected by exposing them to the sun for 2-3 hours.

　　2: Improve personal hygiene: Keep the skin dry, use body powder in summer; change clothes and socks frequently; avoid wearing shoes and socks that are not breathable, not absorbent, or too tight, so that sweat can evaporate in time; try to minimize working in environments that are too hot or humid; treat existing skin ringworm promptly to avoid spreading to other parts of the body.

　　3: Prevent transmission: Avoid using public shoes, towels, and other cleaning utensils; do not walk barefoot in public swimming pools, bathrooms, saunas, gyms, and other places.

　　4: Do not share items such as basins, towels, shoes, socks, and nail clippers with sick family members.

　　5: Enhance the body's ability to resist pathogenic fungi, such as strengthening physical exercise, paying attention to nutrition, which is beneficial for preventing onychomycosis.

　　Isolation and identification of fungi, fungal culture examination. Scraping the broken nail and debris under the nail, under the microscope, fungal hyphae can be seen, and fungal culture is positive. Fungal microscopy often reveals fungal hyphae and spores, which can assist in diagnosis but cannot determine the pathogenic species. Pathological examination can confirm the presence of hyphae and spores, which is the gold standard for diagnosing onychomycosis, and it is noted that fungal culture should be done at the same time as pathological examination.

　　Onychomycosis is a difficult-to-treat chronic infectious disease, so the treatment of onychomycosis should start with daily diet. Below are some dietary treatment methods for onychomycosis:

　　1: Chicken and mushroom soup ingredients: about 200 grams of chicken, appropriate amount of mushrooms, scallions, and ginger. Preparation: slice the mushrooms into thin slices, blanch and drain for later use; cut the chicken into pieces and cook in a pot, then add mushrooms and cook together, stir in cornstarch slurry after boiling, and then it's ready to serve.

　　2: Crucian carp tofu soup Ingredients: 1 crucian carp (about 250 grams), 400 grams of tofu. Preparation: Cut the tofu into 5 cm thick slices, blanch in boiling salt water for 5 minutes and drain for later use; remove the scales and internal organs of the crucian carp, rub with wine and salt for 10 minutes; place the pot on the stove, add cooking oil, and heat for 5 minutes, then sauté the fish slices on both sides, add an appropriate amount of water, bring to a boil over low heat for 30 minutes, add tofu slices, season, and sprinkle with chopped green onions.

　　3: High-protein diet: A high-protein diet is essential for maintaining healthy nails, and egg yolks are a good source of protein. Oatmeal, nuts, seeds, grains, and dairy products are rich in plant protein.

　　4: Eat more vegetables and fruits: Fruits and vegetables should account for 50% of daily diet.

　　The treatment of onychomycosis mainly relies on local external medication, and for patients with multiple onychomycosis or those who have not responded well to long-term local treatment, internal treatment can be considered appropriately.

　　External Treatment

　　(1) 30% glacial acetic acid, 3% miconazole or 10% hydrazine hydrate liniment for external application, twice a day. Scrape off part of the nail before applying the medicine to improve the efficacy.

　　(2) 8% cyclopirox olamine or 5% amorolfine nail polish (both are available on the market).

　　(3) Nail Solvent Therapy: Commonly used 40% urea ointment for packing, wait for the diseased nail to soften every other day, then scrape it off, and continue to use the above drugs.

　　Internal Treatment

　　(1) Itraconazole Oral: 200 mg each time, twice a day, taken continuously for 7 days as one course, then stop for 3 weeks before starting the second course. Two courses are used for finger nail onychomycosis and three courses for toe nail onychomycosis. Fungal examination should be done at the end of each course, and clinical and mycological follow-up should be done once a month for a total of 6 months after the end of the entire course.

　　(2) Terbinafine Oral: 50 mg each time, once a day, taken continuously for 7 days, then take one dose every other day. A total of 14 doses for finger nail onychomycosis and 28 doses for toe nail onychomycosis. Regular follow-up is also required after the course of treatment.

　　Oral Fluconazole: 150 mg each time, 1-2 times a week, taken continuously for more than 4 months.