Fungal Infections

Fungal infections

Cutaneous: dermatophytes, pityriasis versicolor, candidiasis.

Subcutaneous: mycetoma

Systemic: histoplasmosis, candidiasis, aspergillosis

Dermatophytes=ringworm=tinea

•  3 genera: trichophton, microsporum, epidermophyton.

•  All give similar clinical picture.

•  Invade keratin only.

•  Zoophilic and anthropophilic.

•  Clinical features depend on the site

Tinea pedis

* predisposing factors: swimming pools, occlusive footwear.

* Clinically: interdigital scaling

or

Diffuse scaling of sole

or

Recurrent vesicles of the sole

Tinea unguium

•  Toe nail more common than finger nail

•  Free edge becomes yellow or whitish, the infection then spread proximally with darkening of the nail plat and thickening of the nail plate and subungual hyperkeratosis

Tinea corporis

•  Erythematous scaly plaque, grow peripherally and clear centrally annular configuration

•  =active border

•  Close inspection ----- vesicles and pustules

Tinea cruris

•  Affects inguinal fold

•  Erythematous plaque, scale, active border, not affects scrotum. close inspection -----vesicles and pustules

•  Differential diagnosis:

*Flexural psoriasis: look for other sites of predilection of psoriasis

*candidiasis: satellite papules, pustules

*seborrheic dermatitis: look for other sites of predilection of psoriasis

Tinea faciei

•  Erythematous annular plaque- face

•  Diff. diag.:

* seborrheic derm.: nasolabial, eyebrows, eyelashes, ears

* Rosacea: bilateral erythema, telangiectasia

Tinea capitis

•  Patch of hair loss, scales, easily epilated hair.

•  Usually children

•  Zoophilic spp.: Intense inflamm., boggy swelling, pustules = kerion

•  Diff. diag.:

alopecia areata: no inflamm.

trichotillomania: psych. upset, broken hair

Investigations

•  Skin scraping, nail clipping, hair plucking + KOH

•  Culture on sabouraud’s dextrose agar

•  wood’s light ----- green fluorescence in some cases of T. capitis

Treatment

•  Topical imidazoles ex. Clotrimazole, miconazole, econazole ----- Few patches of T corporis, facei, cruris and pedis.

•  Systemic therapy ex. Griseofulvin, terbinafine, imidazoles ex. Fluconazole, ketoconazole, itraconazole ------Tinea capitis, T. unguium, T.incognito, wide spread T. corporis, pedis and feciei

Candidiasis

•  Opportunistic inf.

•  Predisposing: age extremes, D.M, low immunity, ill fitted denture, obesity, antibiotics, pregnancy, and malignancy.

•  Oral thrush: whitish patches, its removal reveal erythematous base

•  Angular stomatitis: whitish patches, soreness

•  Intertrigo: (inguinal, axilla, under the breasts) erythematous patches, satellite papules and pustules

•  Erosio interdigitale: eroded patch affects the webs

Investigations

•  Swab or scrapping for microscope exam yeasts

•  Culture

Treatment

● Correction of underlying pred. factor

● Topical azoles

● Nystatin or amphotericin

● Fluconazole, itraconazole

Pityriasis versicolor

•  Affects young adults, hot humid climate

•  Pityrosporum orbiculare, Keratinophilic and lipophilic.

•  Brownish or hypopigmented round patches, with fine scales

•  Upper trunk, upper arms, neck.

•  Tend to recur.

Investigations

•  Usually it is a clinical diagnosis

•  Scrapping.

•  Wood’s light ----- lemon yellow

Treatment

•  Topical: azoles: *ketoconazole shampoo

* other azole creams

selenium sulphide shampoo

● Systemic : fluconazole, ketoconazole,

itraconazole