Cutaneous Mycoses. Case Study

Cutaneous Mycoses

Dermatophytes (Superficial Mycoses)

Dermatophytes •The superficial (cutaneous) mycoses are usually confined to the outer layers of skin, hair, and nails, and do not invade living tissues. • The fungi are called dermatophytes. •Dermatophytes fungi produce extracellular enzymes (keratinases) which are capable of hydrolyzing keratin.

ETIOLOGIC AGENTS Microsporum species (13 species) (Skin, hair) Trichophyton species (19 species) (Hair, skin, nails) Epidermophyton floccosum (Skin, nails)

Microsporum • Microsporum species form both macro- and microconidia on short conidiophores. • Macroconidia are hyaline, multiseptate, variable in form, fusiform, spindle-shaped to obovate. • Microconidia are hyaline, singlecelled, pyriform to clavate, smoothwalled, 2.5 to 3.5 by 4 to 7 um in size and are not diagnostic for any one species.

Trichophyton • Trichophyton is characterized by the development of both smooth-walled macro- and microconidia. • Macroconidia are mostly borne laterally directly on the hyphae or on short pedicels, and are thin- or thick-walled, clavate to fusiform. • Microconidia are spherical, pyriform to clavate or of irregular shape • Effects on human gives 'Malabar itch', a skin infection, consisting of an eruption of a number of concentric rings, forming patches caused by fungus.

Epidermophyton

• Epidermophyton is a genus of fungus causing superficial and cutaneous mycoses, including E. floccosum, a cause of tinea corporis (ringworm), tinea cruris (jock itch), tinea pedis (athlete’s foot), tinea barbae, tinea versicolor, tinea nigra and onychomycosis or tinea unguium, a fungal infection of the nail bed.

CLINICAL MANIFESTATIONS Tinea corporis - small lesions occurring anywhere on the body.

Tinea pedis - "athlete's foot". Infection of toe webs and soles of feet. Appearance: inflamed, scaly, red and dry.

Tinea unguium (onychomycosis) – infection of nails. Can be a sign of HIV. Appearance: thick and scaly.

Tinea capitis - head. Frequently found in children. Appearance: hair loss (alopecia) and cervical lymph node enlargement are common presentations. Edematous, crusting, scaly, wellcircumscribed, black dot type; hair breaks off at scalp, leaves black dots .

Tinea cruris - "jock itch". Infection of the groin, perineum or perianal area.

Tinea barbae - ringworm of the bearded areas of the face and neck. Appearance: Same as Tinea Capitis.

Malasezzia furfur Tinea versicolor (mild disease)

Tinea versicolor - Characterized by a blotchy discoloration of skin which may itch.

Tinea versicolor (Spaghetti and meatballs)

Disease

Tinea capitis 

Etiological Agent

Symptoms

Microsporum sp. lesion of Trichophyton scalp sp. Epidermophyto n sp.  ringworm

Indentification of organism presence/absence and shape of micro- and macroconidia in scrapings from lesion 

Tinea Microsporum sp. corporis Trichophyton   sp. Epidermophyto n sp ringworm

lesion of trunk, arms, legs 

presence/absence and shape of micro- and macroconidia in scrapings from lesion 

Tinea manus

lesion of hand

presence/absence and shape of micro- and macroconidia in scrapings from lesion 

Microsporum sp. Trichophyton sp. Epidermophyto n sp ringworm

Tinea cruris "jock itch"

Microsporum sp. Trichophyton sp. Epidermophyt on sp ringworm

lesion of groin

presence/absenc e and shape of micro- and macroconidia in scrapings from lesion 

Tinea pedis"

Microsporum sp. Trichophyton sp. Epidermophyt on sp ringworm

athlete's foot" lesion of foot

presence/absenc e and shape of micro- and macroconidia in scrapings from lesion 

Tinea unguiu m

Microsporum sp. Trichophyton sp. Epidermophyt on sp

infection of nails

presence/absenc e and shape of micro- and macroconidia in scrapings from lesion

Diagnosis • Clinical diagnosis (e.g Wood‘s lamp)

• laboratory diagnosis: a) Microscopic examination of (skin, nails, hair) b) Culture (Sabouraud‘s agar)

Dermatophyte Culture

Dermatophyte Culture

Dermatophyte Culture

Trichophyton species

Large, smooth, thin wall, septate, pencilshaped

Microsporum species

Thick wall, spindle shape, multicellular

Epidermophyton floccosum

Bifurcated hyphae with multiple, smooth, club shaped macroconidia (2-4 cells)

Common Medicines: •Griseofulvin •Clotrimazole •Miconazole •Ketoconazole •Itraconazole

The commonly found fungal skin diseases can be categorized into four kinds: • Fungi that only grow on the surface of skin or hair cause the disease called superficial mycoses. • Diseases like athlete foot or ringworm where only a superficial layer of the skin is damaged or infected are known as cutaneous mycoses or dermatomycoses. • Diseases where the subcutaneous, connective, and bone tissue that lie under the superficial layer are affected are

• The only fatal kind of mycoses is the Deep or Systematic mycoses where even the internal organs can be harmed badly by Fungi and can also become widely disseminated. These generally begin from internal parts like lungs and slowly spread to the other parts as well. • The diseases that are not caused in the regular course but are caused due to inefficiency of Immune system of Human Body are known as Opportunistic mycoses.

MODE OF TRANSMISSION Cutaneous mycoses •infections strictly confined to keratinized epidermis (skin, hair, nails) are called dermatophytoses ringworm & tinea 39 species in the genera Trichophyton, • Microsporum, Epidermophyton communicable among humans, animals, & soil infection facilitated by moist and chafed skin.

• Ringworm of scalp (tinea capitis) affects scalp & hairbearing regions of head; hair may be lost • Ringworm of body (tinea corporis) occurs as inflamed, red ring lesions anywhere on smooth skin • Ringworm of groin (tinea cruris) “jock itch” affects groin & scrotal regions • Ringworm or foot & hand (tinea pedis & tinea manuum) is spread by exposure to public surfaces; occurs between digits & on soles • Ringworm of nails (tinea unguium) is a persistent colonization of the nails of the

•

Symptoms of Tinea Pedis Athlete's foot causes scaling, flaking, and itching of the affected skin. Blisters and cracked skin may also occur, leading to exposed raw tissue, pain, swelling, and inflammation. Secondary bacterial infection can accompany the fungal infection, sometimes requiring a course of oral antibiotics.

Diagnosis • Athlete's foot can usually be diagnosed by visual inspection of the skin. • a biopsy of the affected skin (i.e. a sample of the living skin tissue) can be taken for histological examination. • A Wood's lamp, is not usually helpful in diagnosing tinea pedis since the common dermatophytes that cause this disease do not fluoresce under ultraviolet light. However, it can be useful for determining if the disease is due to a non-fungal afflictor.

Transmission From person to person -communicable disease. -transmitted in moist environments where people walk barefoot, such as showers, bath houses, and locker rooms -transmitted by sharing footwear with an infected person, or less commonly, by sharing towels with an infected person.

Case discussion L.J., a 23 yr old male, single, and a professional basketball player, came to the physician's office due to severe itchiness oh his feet.

History of past Illness The condition started around 3 weeks prior to consultation, when he noted itchiness in his feet, especially in the areas in-between his toes. it involved scaling in the said areas, as well as slight redness, which later spread to the rest of his feet.

Review of Systems No noted fever, headache, difficulty of breathing, chest pains, abdominal discomfort nor swelling in other parts of the body. PAST MEDICAL HISTORY AND FAMILY MEDICAL HISTORY The patient as not previously diagnosed with diabetes, asthma, hypertension, or heart disease. There was note of an incidental finding of heart disease in his grandfather. The rest are unremarkable.

PERSONAL,SOCIAL AND OCCUPATIONAL HISTORY L.J. works as a professional basketball player. He is sure he did not wade in flood waters recently. He also could not recall ever being bitten by any animal for the past two months. He, however, admitted he noticed his team mate came up with similar symptoms a few weeks before he experienced the same thing. They share lockers.

Physical Examination The patient had a BP of 110/80 mmHg, a heart rate of 72bpm, afebrile, had pink conjunctivae, anicteric sclerae and no noted cervical lynphadenopathies. His breath sounds were equal, clear, with no noted rales nor wheezes . He had an adynamic precordium, normal rate and regular rhythm, with no noted murmurs. Abdomen was soft, non-tender. His extremities had pink nail beds, he had full and equal pulses with no signs of edema. Examination of his feet, however, revealed erthyma and scaling,

Prevention at home • Bathroom hygiene • Frequent laundering Wash sheets, towels, socks, underwear, and bedclothes in hot water • Avoid sharing • Prevention measures in public places Wear shower shoes in public places and make sure you wash feet, especially in between toes then dry thoroughly.

Personal prevention measures • Wear lightweight cotton socks to help reduce sweat. • Dry feet well after showering, paying particular attention to the web space between the toes. • Keep shoes dry by wearing a different pair each day. • Do not use socks that are not yet washed.

Treatment