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Different types of dermatophytosis affect the body in different ways. Some types are mild, but some of them are serious. The common types of dermatophytosis include: 1. Tinea Pedis: Tinea pedis, also called Athlete's foot, is a common skin infection of the feet caused by fungus. It may infect any paRead more
Different types of dermatophytosis affect the body in different ways. Some types are mild, but some of them are serious. The common types of dermatophytosis include:
1. Tinea Pedis: Tinea pedis, also called Athlete’s foot, is a common skin infection of the feet caused by fungus. It may infect any part of the foot, but most often occurs between the toes (interdigital), with the space between the fourth and fifth digits most commonly afflicted.
2. Tinea Unguium: Tinea unguium, also known as Onychomycosis, is a fungal infection of the nail. Typical symptoms include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Older people are affected more frequently, and males are affected more often than females.
3. Tinea Corporis: Tinea corporis also called tinea circinata and tinea glabrosa, is a superficial fungal infection of the arms and legs, especially on glabrous skin. Tinea corporis usually affects exposed skin but also might be spread from other infected sites. It can be acute (sudden onset and rapid spread) or chronic (slow extension of a mild, barely inflamed, rash).
4. Tinea Cruris: Tinea cruris, also referred to jock itch, is a fungal infection in the groin area in either sex, but more often in males. The infection results in itching or red with flaking skin.
5. Tinea Manuum: Tinea manuum or tinea manus, is a fungal infection of the hand. It is more aggressive than tinea pedis but similar in look. The observed symptoms in tinea manuum patients are itching, burning, cracking, and scaling.
6. Tinea Capitis: Tinea capitis, also known as herpes tonsurans and scalp ringworm, is a cutaneous fungal infection of the scalp. Its typical presentation is single or multiple patches of hair loss that may be accompanied by inflammation, scaling, pustules, and itching. Tinea manuum is predominantly seen in pre-pubertal children.
7. Tinea Barbae: Tinea barbae, also called Barber’s itch, is a fungal infection of the hair due to the infection around the bearded area of men. The transmission of tinea barbae is more often from animal to human than human to human.
8. Tinea Faciei: Tinea faciei is a fungal infection of the face. It usually results in a red rash on the face, followed by patches of small, raised bumps, and the skin may peel after treatment. Tinea faciei can spread easily to any region of the skin.
9. Tinea Versicolor: Tinea versicolor, also called pityriasis Versicolor, is a fungal infection of the skin. It is caused by yeast, and predominantly in adolescents and young adults. Tinea versicolor gets worse in hot, humid climates and may disappear during cool weather.
10. Tinea Nigra: Tinea nigra is a superficial mold infection of the stratum corneum that causes dark brown to black painless patches on the palms of the hands and the soles of the feet. Its clinical presentation is a single painless sharply demarcated brown to black macule on the palmar surface of the hand or finger or on the plantar surface of the foot or other sites.
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Diagnostic Methods for Dermatophyte Infections: 1. Potassium hydroxide (KOH) microscopy: Values: aids in visualizing hyphae and confirming the diagnosis of dermatophyte infection Procedure: obtain scale from the active border of a lesion, pull out several loose hairs from the affected area or, in thRead more
Diagnostic Methods for Dermatophyte Infections:
1. Potassium hydroxide (KOH) microscopy:
Values: aids in visualizing hyphae and confirming the diagnosis of dermatophyte infection Procedure: obtain scale from the active border of a lesion, pull out several loose hairs from the affected area or, in the case of nails, obtain subungual debris. A moist cotton swab rubbed vigorously over the active border of a lesion works as well as a scalpel blade and is safer. Transfer the scale, hair, or debris to a glass slide, and add a few drops of 10% to 20% KOH. For nail material or hair, gently warm the slide. The wet-mount preparation is then examined under a microscope (×400) with back-and-forth rotation of the focus knobs. This technique aids the visualization of hyphae (branching, rod-shaped filaments of uniform width with lines of separation [septa]). In tinea capitis, the hair shaft may be uniformly coated with minute dermatophyte spores.
2. Wood’s lamp examination (ultraviolet light):
Value: generally of limited usefulness, because most dermatophytes currently seen in the United States do not fluoresce; may have value in the following situations: For diagnosing a brown, scaly rash in the scrotum or axilla: erythrasma, caused by the bacterium corynebacterium minutissimum, fluoresces a brilliant coral red, whereas tinea cruris or cutaneous candidal infections do not fluoresce.
For diagnosing tinea (pityriasis) Versicolor, which fluoresces pale yellow to white
For diagnosing tinea capitis caused by two zoophilic Microsporum species that fluoresce blue-green.
3. Fungal culture:
Value: slow and expensive, but useful to confirm the diagnosis of onychomycosis when long-term oral therapy is being considered
Procedure*: Skin, nail, or hair scrapings are sent in a sterile container for inoculation on Sabouraud’s dextrose agar by a hospital or reference laboratory. The culture usually takes 7 to 14 days to be declared positive; it must be held for 21 days to be declared negative.
4. Skin or nail biopsy:
See lessValue: may guide treatment decisions when the diagnosis is difficult to establish, a dermatophyte infection has not responded to previous treatment, or KOH microscopy is negative in a patient with dystrophic nails.