Onychomycosis of the nail bed type

　　From the perspective of clinical pathogenic conditions, fungi can be divided into two major categories: superficial fungi and deep fungi. Superficial fungi only invade hair, skin, and nails. Superficial fungal diseases are extremely common in China, including tinea capitis, tinea corporis, tinea cruris, tinea pedis, pityriasis versicolor, and onychomycosis. Deep fungi mainly invade internal organs, bones, and the nervous system, and can also affect the skin and mucous membranes. Common deep fungal diseases include sporotrichosis, chromoblastomycosis, actinomycosis, and cryptococcosis. The genus Candida can invade the skin, mucous membranes, nails, and internal organs. Onychomycosis of the nail bed type is mainly caused by dermatophytes such as Trichophyton soudanense and Trichophyton violaceum, leading to nail plate infections.

　　1. Complications such as paronychia, subungual abscess, ingrown nails, and necrosis of the distal phalanges can occur.

　　2. Paronychia is an inflammatory reaction involving the skin folds around the nail, presenting as acute or chronic suppurative, tender, and painful swelling of the perinail tissue, caused by paronychia abscess. When the infection becomes chronic, transverse ridges appear at the base of the nail, and new ridges appear with recurrence. For those with paronychia that has invaded under the nail to form an abscess, or ingrown nails complicated with infection, nail avulsion and drainage should be performed.

　　3. Dry necrosis of the distal phalanges is mainly seen in diabetic patients.

　　The invaded nail plate presents a diffuse milky white change, the surface of the nail is glossy, the thickness of the nail is normal, there is no hyperkeratosis thickening of the nail bed, the nail plate is tightly connected with the nail bed, and there is no nail separation. Fungus invasion into the nail can secrete protease to decompose keratin after growing on the nail plate, destroy the nail tissue, and cause changes in the shape, texture, and color of the nail, damaging the aesthetic appearance of the nail. Especially for many young people, many patients may shrink their hands and feet due to onychomycosis. Our daily work and life cannot do without the help of our hands. Once fungus invades and onychomycosis is contracted, the choice of work may be limited; the nail grows at the end of the hand and has a protective function. Once it is sick, the hand is prone to injury due to collisions, and the function of the fingers is damaged. In severe cases, it may cause pain, and once injured, pathogenic bacteria are easy to invade, thus causing complications such as paronychia, nail bed inflammation, and finger skin abscess, which may lead to severe systemic symptoms such as erysipelas or cellulitis.

　　One level of prevention

　　1. Pay attention to personal hygiene, develop good hygiene habits such as frequent hand and foot washing, and trimming nails. People with excessive foot sweat should wear more breathable shoes and can apply foot powder to keep the feet dry, or wear anti-fungal shoes and socks.

　　2. Those who have already been diagnosed with tinea cruris or tinea pedis should actively seek treatment until completely cured, to avoid cross-infection.

　　3. Do not develop the habit of scrubbing feet or picking at them, especially for patients with tinea pedis.

　　4. For those with tinea pedis, to prevent the infection of onychomycosis, apply a 30% acetic acid solution on the nails 2 to 3 times a week.

　　Two levels of prevention

　　The treatment of onychomycosis should be carried out simultaneously with the concurrent tinea pedis, and long-term and patient treatment is required. The active fungus of onychomycosis hides deeply at the back of the nail, and the drugs applied externally generally cannot reach the affected area, making it difficult to cure. If the upper protective layer (diseased nail) is removed first, and then anti-fungal drugs are applied externally, the drugs are more likely to reach the affected area.

　　1. Generally, use a sharp blade to chop and scrape off the brittle parts of the diseased nail until it does not bleed or cause pain, then apply a 30% acetic acid solution or 5% iodine tincture externally until there is a slight sense of pain, indicating that the medicine has reached the bottom layer. Use the medicine 1 to 2 times a month, continuously for several months, until the diseased nail is completely removed and the normal new nail is fully grown.

　　2. It can also be soaked in 10% glacial acetic acid solution several times a day, but the effect may be slightly slower.

　　3. Nail Avulsion Therapy

　　(1) Apply 30% to 40% urea hard paste to the affected nail, change it every 4 to 5 days. The nail can gradually soften, the nail plate and nail bed can separate, making it easier to remove. If unsuccessful, the medication can be repeated.

　　(2) Use salicylic acid lactate ointment instead of urea hard paste.

　　(3) Under local anesthesia, surgical nail avulsion is performed, and gauze soaked in Vaseline can be used to wrap the wound if necessary. Apply 3% salicylic acid ointment first after one week, and gradually increase the concentration, finally using a mixture of benzyl benzoate ointment and iodine tincture alternately for external application until a new nail grows out.

　　Fungal Culture Examination:

　　1. The causative agent is primarily Trichophyton soudanense, which can also be caused by Trichophyton violaceum, both of which have the characteristic of affinity for keratin.

　　2. PAS staining of nail tissue shows a large amount of fungal hyphae within the nail plate, which are parallel to the nail plate, penetrate the entire nail plate, and branch transversely and longitudinally within the nail plate. The nail bed is without inflammation and is tightly connected to the subnail plate, and there are no hyphae in the nail bed.

　　1. 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 soy products are rich in plant protein. Eat more fruits and vegetables: fruits and vegetables should account for 50% of daily diet. Supplement nutrients.

　　2. High-calcium foods:High-calcium foods can promote nail repair, such as milk, kelp, shrimp skin, animal bones, and soy products like tofu and soy milk. There are also eggs. Vegetables such as chrysanthemum, radish, mushrooms, black fungus, broccoli, broccolini, amaranth, and spinach have high calcium content.

　　Treatment Methods for Endonychia Onychomycosis:

　　1. General Treatment: Avoid scratching skin lesions on other parts of the body with your hands. Keep fingers and toes clean to prevent infection. Improve diet and lifestyle, and pay attention to mental nourishment.

　　2. Actively treat associated tinea infections.

　　3. Antifungal (Daktarin) Treatment.

　　4. Surgical Treatment: Remove the affected nail and配合外用抗真菌制剂.