CUTANEOUS FUNGAL INFECTION
CUTANEOUS FUNGAL INFECTIONThe most important charac. of the ring worm fungi (dermatophyte , tinea) , is their ability to invade keratinized structures without being able to penetrate the deeper living cells . The disease which they cause are therefore limited to hair , nails , & horny layer of the epidermis . The fungi are classified in to three main genera namely microsporum , epidermophyton , & trichophyton . There are different species within these genera . Among these 3 genera , there are 3 types of dermatophytes according to the source of origin these are :-
CUTANEOUS FUNGAL INFECTION
Zoophilic . Anthropophilic :- are responsible for epidemic . Geophilic . Dermatophytosis on certain parts of the body produces certain distinctive features charac. of that particular site . For this reason dermatophytoses are divided in to the following : Tinea capitis . 5-Tinea manum . Tinea barbae . 6-Tinea cruris . Tinea faciei . 7-Tinea pedis . Tinea corporis ( circinata ) .8-Tinea unguim .CUTANEOUS FUNGAL INFECTION
Diagnosis :- Wood light examination :- hair , but not the skin of the scalp fluoresces with brilliant-green color if infected with microsporum species . Fungal infection of the skin do not fluorescence , except for tinea versicolor , which produces yellow fluorescence . Potassium hydroxide wet mount preparation(scraping test) for absolute diagnosis is direct visualization of the branching hyphae in the keratinized material under the microscope . To do this some scale should be scraped off from the periphery of the lesion . Culture :- to know species of dermatophyte . a-Sabouraund`s agar . b- Mycosel agar .TINEA CAPITIS
Is an infectious disease occurring chiefly in school children , more in boys than girls . When the fungi invade the hair the mycelium is always found inside the hair . While the spores either present inside the hair (endothrix ) or outside the hair ( ectothrix ). Some fungi causes the infected hairs to fluoresce under wood light with brilliant green while others are not . Clinical types of tinea capitis :- Non inflammatory type :- including a- dry scaly type . b- black dot type . Inflammatory type :- including a- kerion . B- favus .Tinea Circinata ( Corporis )
Charac. Clinically by circular patches which spread out peripherally , healing in the center & so forming the ring from which the disease gets its name . They are red , scaly & especially in the case of animal origin , may be vesicular or pustular & very inflammatory . The lesion are usually single or few in number , but may be multiple . Incubation period 3-7 days . Differential diagnosis :- Discoid eczema . Psoriasis . Pityriasis rosea .TINEA CRURIS
The disease is more common in hot summer months , when there is high humidity . Men more than women . Affecting the upper inner thighs extending from the groin downwards . The disease begins as red maculo-papules which spread peripherally & finally form red patches several inches across . The edge is more inflamed than the older central portion , & may be vesicular or pustular . The irritation is intense . Differential diagnosis :- 1- candida . 2-seborrheic dermatitis . 3- intertrigo . 4- flexural psoriasis . 5- erythrasma .TINEA PEDIS
It mainly affect adolescent & young adult males . Spread by the transfer of infected fragments in the bathroom changing rooms , & swimming baths . Once infection has occurred , the patient becomes a carrier , the fungus persist in clinically normal skin , thus ensuring further relapse . The condition consist of thick , white , peeling , macerated skin between the toes , together with redness , soreness , itching , & cracking . Usually affect tow or more toe cleft , although it may remain unilateral for months or even years . The condition also frequently affect the soles . Differential diagnosis :- pomphplyx
TINEA INCOGNITO
Is modified ring worm infection when treated with topical steroid which decreases inflammation & give the false impression that the rash is improving . Scaling may not be present , active border may not be present .CANDIDIASIS (MONILIASIS)
The yeast like fungus candida albican & few other candida species are capable of producing skin , mucus membrane , & internal infections . The organism lives with the normal flora of the mouth , vaginal tract , & gut . It reproduces through budding of the oval yeast forms . Pregnancy , oral contraceptive , antibiotic therapy , diabetes , skin maceration , topical steroid therapy , certain endocrinopathies , & factors related to depression of CMI ; allow the yeast to become pathogenic & produce budding spores & elongated cells (pseudohyphea) or true hyphea with septate wallsCandidiasis
The pseudohyphea & hyphea are indistinguishable.Culture results must be interpreted carefully because the yeast is part of the normal flora in many parts . The yeast infects only the outer layers of the epithelium of the skin & mucus membrane ( stratum corneum) . The primary lesion is pustule , the content of which dissect horizontally under the stratum cornium & peel it away . Clinically , this process results in a red-denuded , glistening surface with a long , cigarette paper-like scaling (collaret scale) in the advancing border . Infection of the m.m. of the mouth & vaginal tract accumulate scale & inflammatory cells that develop in to white or white-yellow , cruddy material .CANDIDIASIS
Yeast grows best in a warm , moist environment , therefore, infection is usually confined to the m.m. & intertriginous areas . The advancing infected border usually stops when it reaches dry skin . Clinical types of candidiasis :- 1.Oral candidiasis (thrush) :- creamy-white , easily removable , pseudomembranouse patches are found on the buccal mucosa & tongue . Predisposing factors :- it is more common in a-babies . B- patient treated with antibiotic . c-immunosuppress patient . Differential diagnosis :- milk patchCANDIDIASIS
Clinical types of candidiasis :- 2-Angular stomatitis (perleche):- sore fissure in the depth of the skin fold .Erythema , scaling , & crust form at the sides of the fold . Patient lick & moisten the area in an attempt to prevent further cracking but this aggravate the problem . Predisposing factors :- lip licking , biting , poorly fitting denture . Differential diagnosis :- B12 deficiency , staph. infection .CANDIDIASIS
Clinical types of candidiasis :- 3- Candidal intertrigo :- affecting folds of the genitals ,groin, armpit , between buttocks , under large pendulous breasts , under overhanging abdominal folds , or in the umbilicus . Clinically present as pinkish moist patches surrounded by thin , overhanging fringe of some what macerated epidermis (collaret scale) , commonly there is tiny superficial , white pustule are observed closely adjacent to the patch . Differential diagnosis:- a- tinea cruris . b- erythrasma c- flexural psoriasis . d- intertrigo . e-seborrhiec der.CANDIDIASIS
Clinical types of candidiasis :- 4-candidal vulvovaginitis :- the patient present with sever pruritus , irritation , & extreme burning . The labia may be hyperemic , swollen , & eroded . Vaginal discharge is not profuse but is thick , & tenacious . this type of infection may develop during pregnancy , DM. , prolong therapy with broad spectrum antibiotic , or tamoxifen treatment . If the partner has candidal balanitis & is not recognized , repeated infection of the partner may result . 5-candidal balanitis . 6- dipper candid. 7-candidiasis of small skin fold . 8- candidal paronychia .