Tinea nigra

Tinea nigraTinea nigra is a superficial ringworm usually caused unusual Hortaea wemeckii. It appears as a hyperpigmented macule on her hands. Plants and rarely other parts of the body may be affected. Although nigra can be alarming aspect is unusual because of high incidence and potential confusion with a more severe medical condition (malignant melanoma), tinea nigra is a benign and easily curable disease.
After tinea nigra is described and diagnosed based on patient history, physical examination and appropriate laboratory tests indicate a treatment to eradicate the fungal infection. Dermatological agents are used as salicylic acid, tretinoin, topical imidazoles, piridone topical alilamine.
Because the infection is considered to occur after secondary inoculation trauma, patients should avoid sources of contamination such as soil, compost and rotted wood. Tinea nigra is a benign superficial fungal infection that does not cause serious complications. It is curable and treatment is not appropriate.
Pathogenesis and causes
Tinea nigra is a superficial mycosis of the stratum corneum. Infection occurs as a result of inoculation out of a contaminated source such as soil, compost timber or a trauma to the affected area. Typical incubation is 2-7 weeks. Lipophilic fungus shows adhesion to human skin. It is found exclusively in the stratum corneum and stratum lucidum does not extend to.Fungus takes nutrients from the breakdown of fats. It is tolerant to salt and a low pH environment. Cause changes to skin pigmentation patches colored black by the accumulation of substance melaninlike in fungi. Ringworm tends to occur in areas with a higher concentration of eccrine glands. Hyperhidrosis seems to be a risk factor.
Signs and symptoms
Tinea nigra is most common in pediatric and adolescent populations, yet people of all ages can be infected. Generally patients are asymptomatic tinea nigra. Rarely pruritus can be reported. The absence of any discomfort the patient's decision to postpone doctor.
Physical examination.Tinea nigra is characterized by the presence of a brown-black macules painless. The macula appears as a black dot initially insidious. Macular hyperpigmentation varies from brown to black up similar to silver nitrate. Edges are typically discrete. Pigmentary changes appear smooth. Typical lesion is solitary, although multiple lesions may be present. Solitary lesions are located on the surfaces and planting palm, but can extend to the fingers. Areas like the neck or chest are rarely affected.Shape ovoid lesion varies and can be round or irregular. The lesion grows slowly in a few weeks or months. Size varies from a few millimeters to inches in diameter, depending on the duration of infection. Other natural elements such as redness or mercy are absent. Rarely is this peeling.
Diagnosis
Laboratory studies:Microscopic examination of scales peilii-treated with potassium hydroxide showed septated hyphae, branched cxare containing black pigment in the wallsIncreases intro-week culture.Histological examination of biopsy specimens showed mild hyperkeratosis and acanthosis. One can describe a lymphoma perivascular infiltrates in the papillary layer of dermis and subpapilar.The differential diagnosis is made with the following diseases: Addison's disease, dysplastic nevus, malignant melanoma, nevi melanocitici, syphilis, candida, pint, chemical contamination.
Treatment
Topical antifungal preparations are used to eradicate the infection. Dermatological agents are used to treat tinea nigra due to their action on the skin. They can help remove excess keratin in hyperkeratotic skin disorders or modify the cellular turnover. Or fungicides are used alongside medical fungistaticele.
Salicylic acid peeling of the stratum corneum determined by dissolving the intercellular cementum without affecting the structure of viable dermis. Tretinoin topical drops coalescence of follicular epithelial cells and stimulate their mitotic activity with a rapid turnover of epithelial cells.
Imidazolii topical antifungal spectrum are typically used for tinea pedis and tinea but are useful nigra. Examples: Clotrimazole, ketoconazole, miconazole. Piridonele are topical agents with broad spectrum activity anticandidozica, antidermatofitica and antibacterial. Examples: Ciclopirox. Topical Alilaminele epoxidaza inhibit a key enzyme in the biosynthesis of squalene sterol in fungi fungus causes death. Examples: terbinafine. Fungistatic agents not only kill fungi prevent their replication. Examples: undeclenic acid.