Onychomycosis

Introduction to onychomycosis Onychomycosis is a nail infection caused by dermatophytes, yeasts and non-dermatophytic filamentous fungi (mold). A disease caused by dermatophytes alone is called hyperthyroidism. (tineaunguium). Most of the nails are transmitted directly from the athlete's foot. The nail file may be transmitted by handcuffs or directly contacted by the rickets of other parts of the body. The nail is commonly called "grey nails", which is called chicken claw wind, putty nails, etc. Most of them have been spreading for a long time, so that the day is not caused by Rongjia. basic knowledge Sickness ratio: 0.5%-1% Susceptible people: no specific population Mode of infection: contact spread Complications: paronychia

Cause of onychomycosis

(1) Causes of the disease

Onychomycosis is still the most common dermatophytes, about 77.6%, mainly T. rubrum (85%), followed by T. rubrum (12%), flocculent epidermis (2% to 3) %), its decomposed keratin, produces invasive enzymes and invades and destroys normal tissues, leading to primary A infection, secondary A infection occurs after other factors damage A, mostly by yeast without keratin And fungi caused by yeast, about 90% of Candida, the other fungi are mainly Penicillium and Aspergillus, as well as Geotrichum candidum, Mycobacterium and Mucor, Acremonium, etc. It has been suggested that the disease is an autosomal dominant genetic disease associated with keratin mutations, and some people have this genetic quality.

(two) pathogenesis

Onychomycosis is still the most common dermatophytes, about 77.6%, mainly T. rubrum (85%), followed by T. rubrum (12%), flocculent epidermis (2% to 3) %), its decomposed keratin, which produces invasive enzymes and invades and destroys normal tissues, leading to primary nail infection. The fungus begins to invade the distal parietal layer of the distal margin, and then invades the underside of the deck, gradually causing discoloration of the deck. Loss of normal smooth appearance, accumulation of debris in the stratum corneum of the nail bed under the deck, causing the deck to separate from the nail bed (Fig. 1), or being cut off by the patient, leaving the entire deck missing (Fig. 2), leaving a hyperkeratotic nail bed Some fungi can produce different pigments such as short brown mold producing brown, globular husk mites producing black, etc. It has been suggested that the disease is an autosomal dominant genetic disease related to keratin variation, and some people have this genetic quality.

Onychomycosis prevention

Population prevention: Prevention of hyperthyroidism is to remove the source of self-infection, that is, to cure body lice, femoral hernia, hand sputum and athlete's foot. This is the most active preventive measure for preventing hyperthyroidism. Therefore, the prevention of hyperthyroidism can be seen in the skin.

Primary prevention

(1) Pay attention to personal hygiene, develop good hygienic habits of washing hands, washing feet, and trimming the toes. People with more sweat should wear more breathable shoes and can hold the feet to keep the feet. Dry, or wear mildew shoes, socks.

(2) Those who have suffered from femoral hernia or hand, foot and ankle should be treated actively until they are completely cured to avoid cross-infection.

(3) Do not develop the habit of lameness and lameness, especially for patients with athlete's foot.

(4) For those with hand, foot and ankle, in order to prevent the infection of the nails, apply a 30% glacial acetic acid solution on the nails 2 to 3 times a week.

2. Secondary prevention

The treatment of hyperthyroidism should be treated concurrently with concurrent hand and foot spasm, and it needs long-term patient treatment. The hyperthyroidism activity fungus is hidden deep in the back end of the nail. Generally, the drug of the external hemorrhoids does not reach the affected area, so it is difficult to cure. The maintenance layer (bad armor) is removed, and then the antifungal drug is applied externally, so that the drug easily reaches the affected area.

(1) Generally, a quick blade can be used to cut the diseased part of the diseased piece every day, scrape it off, prevent it from bleeding or causing pain, and then lick 30% glacial acetic acid solution or 5% iodine, until the pain is slightly felt, indicating that the drug has arrived. The bottom layer, 1 or 2 times a month, for several months, until the disease is removed, the normal newborn A is fully grown.

(2) It can also be soaked in 10% ice vinegar solution several times a day, but the effect may be slightly slower.

(3) Pulling therapy

1 Use 30% ~ 40% urea hard plaster on the diseased nail, every 4 to 5 days to replace, the disease can gradually soften, the deck and the nail bed separated, making it easy to remove, if not successful, can be repeated.

2 replace the urea plaster with salicylic acid lactic acid ointment.

3 local anesthesia surgery, pulling the wound with Vaseline gauze if necessary, after 1 week, first apply 3% salicylic acid ointment, then gradually increase the concentration, and finally use compound benzoic acid ointment and iodine alternately, until the new one grows out.

Onychomycosis complications Complications

Symptoms of onychomycosis common symptoms keratin thickening

According to the different clinical features of nail damage, onychomycosis can be divided into the following four types:

1. Distal subungual onychomycosis (DSO)

This is the most common type. The fungus begins to invade the distal parietal layer of the distal margin and invades the underside of the deck, gradually causing the deck to discolor and lose its normal smooth appearance. The debris of the stratum corneum is deposited under the deck, making the deck The nail bed is separated and detached, or cut off by the patient, so that the entire deck is missing, leaving a hyperkeratotic nail bed. Some fungi can produce different pigments such as short brown mold, brown, and black stalks, and the toe of the pathogen is Trichophyton rubrum, Trichophyton rubrum, Fusarium oxysporum, Aspergillus oryzae, Aspergillus, Fusarium, Cephalosporium, Candida albicans, Candida tropicalis, Candida parapsilosis, Geotrichum candidum and P. oxysporum The fingers are Trichophyton rubrum and Candida albicans.

2. White superficial onychomycosis (WSO)

Less common, the fungus directly invades through the shallow deck, forming small, superficial white spots and increasing, fusion, and finally the nail becomes soft, rough, amber, the toe of the pathogen is Trichophyton, cephalosporin Mildew, Aspergillus and Fusarium, red Trichophyton are rare.

3. proximal subungual onychomycosis (PSO)

Typical can be seen at the proximal end of the fingernails, starting like white spots, can be expanded into white spots, showing the bottom of the deck involved, but the entire nail can be involved, the original hair is rare, trauma, diabetes, psoriasis, chronic paronychia And peripheral vascular disease can be secondary to this type of infection, this type increases with the rise of AIDS in foreign countries, the pathogen toe is red T. rubrum, Trichophyton rubrum, Rhododendron chinense, Trichophyton rubrum, Magni Trichophyton, the finger is Trichophyton rubrum and M. gigas.

4. Total dystrophic onychomycosis (TDO)

For the final stage of the development of the above three types, the full-level A is involved.

In addition, there are two special types: fungal black armor, caused by melanin-producing non-dermatophytic fungi and yeast such as Trichophyton rubrum and Alternaria sinensis, which is characterized by mediastinal black armor and chronic The primary nail infection of the skin mucosal candidiasis is a dystrophic candidiasis involving the full thickness of the deck. Due to the accumulation of debris under the armor, the deck is easily peeled off and the hyperkeratosis of the nail bed is left behind.

Examination of onychomycosis

Fungi can be found at the toe of the pathogen or for the genus Trichophyton, Cephalosporium, Aspergillus and Fusarium.

1. Mycological examination is sufficient to collect enough specimens. The distal nail can be used with a curette, a dental spatula and a screwdriver to remove the debris. The proximal nail can be used with a diamond or a scalpel. The white superficial model is available. Cursor, scrape the nails near the nail bed at the junction of the lesion and the normal area, add 10% KOH for direct microscopic examination, and see the branch hyphae to support the diagnosis, mold, penicillium, Aspergillus, cephalosporin, Fusarium, The Helminthosporium and Candida albicans can form hyphae and pseudohyphae and are confused with dermatophytes. The sandcastle agar culture should be cultured for 6-8 weeks using a two-tube method (one without actinomycin).

2. Histopathological keratin thickening, loose, keratinocytes are arranged in a basket-like shape, with varying degrees of damage, visible fissures, cavities, see the slender regular hyphae or joint hyphae in the deck, suggesting that the skin is paralyzed The fungus has many hyphae growth, a few oblique or longitudinal growth, and some grow along the cavity wall, often located in the outer or inner layer of the deck. When the deck is seriously damaged, densely arranged bacteria can be seen in the entire deck. Silk and spores; if small or elliptical small cells are detected, aggregated into clusters, buds, pseudohyphae and thick-walled spores are visible, suggesting yeast, these cells are mostly located in the inner layer of the deck, and a few are found outside the deck. Layer or middle layer; if there are irregular coarse hyphae in the deck, there are leaf-like structures, the color is uneven, some are brown or dark brown, and the growth is disordered, suggesting that it is a non-dermatophytic fungus.

Diagnosis and diagnosis of onychomycosis

The diagnosis of onychomycosis depends on direct microscopy and culture of the nails.

Diagnose based on

1. Onset characteristics;

2. Characteristics of disease damage;

3. Direct microscopic examination of the nails reveals hyphae, and the fungal culture is positive.

Identification with non-dermatophytic fungi.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.