nails fungal infections

Dr. YOUSRA MHD. HIKMAT BATARNI

MEDICAL COMMISSION

Fungal Nail Infections

Definition

Different fungal organisms may infect the nails, with different patterns of presentation, affecting any part of the nail from the nail bed to the nail matrix and plate.

The most common result is a poor cosmetic appearance of the affected nail(s); however, the condition may also cause pain, disfigurement and functional impairment.

Epidemiology

This is one of the most commonly occurring dermatological conditions.

prevalence reports a range from 3-26% worldwide.

The incidence of new cases of onychomycosis (OM) appears to be rising due to the increasing prevalence of diabetes and more ageing population.

Risk factorsAge : adults are 30 times more likely than children to

suffer the condition.Immunosuppression illness or medications that

suppress immune responses greatly increase the likelihood of developing OM.

Diabetes mellitusCutaneous fungal infection co-exists with OM in about

30% of cases. Living in a warm, humid climate.Participation in athletic/sporting activities, regular

communal bathing and occlusive footwear.Prior trauma to the nail.

Infecting organismsDermatophytes causes over 90% of cases.

Yeasts : These cause 8% of total infections, particularly Candida albicans.

Non-dermatophyte moulds These cause about 1-10% of total infections in the general population -

 However, they are the predominant causative organisms in patients who also have HIV.

Presentation

Distal and lateral subungual onychomycosis (DLSO)

Distal and lateral subungual onychomycosis (DLSO)•Nearly always caused by dermatophytesCan either affect a healthy nail or one already diseased - eg, by psoriasis.

•Affect the hyponychium (epithelium of nail bed), often at the lateral edges initially.

•Spread proximally along the nail bed, causing creamy/buff discolouration, subungual hyperkeratosis and onycholysis.The nail plate is not affected initially but may become so in time.

•May be confined to one side of the nail or spread sideways to involve the whole nail bed.

Superficial white onychomycosis (SWO)SWO is less common than DLSO:It is usually due to dermatophyte infection .It presents as white chalky plaque on the proximal

nail plate, almost exclusively on the toenails.The surface of the nail plate is affected rather than

the nail bed. The nail plate may become eroded and even lost.

There is white rather than creamy discolouration.Onycholysis is not usually a feature.Concurrent tinea pedis is less common than in DLSO.

Superficial white onychomycosis (SWO)•SWO is less common than DLSO

•It is usually due to dermatophyte infection .It presents as white chalky plaque on the proximal nail plate, almost exclusively on the toenails.

•The surface of the nail plate is affected rather than the nail bed. The nail plate may become eroded and even lost.

•There is white rather than creamy discolouration.

Proximal subungual onychomycosis (PSO)•PSO is uncommon:•Candidal OM occurs in three different types:

•Candidal paronychia: initially appears as oedema, erythema and pain of the nail fold, from which pus can be expressed.•Subungual abscess with DLSO•Total nail dystrophy

•Causes chronic paronychia with secondary nail dystrophy.

Total dystrophic onychomycosis (TDO)•Represents a long-standing, severe, end-stage disease progressing from all the above clinical patterns.

•Complete destruction of the nail plate is observed.

Differential diagnosis Only about 50% of discoloured or dystrophic-appearing nails have a fungal

infection confirmed with dermatophyte on culture. Other causes include:Onychogryphosis (thickening and distortion of the nail, typically of the big

toe, thought to be due to previous nail bed trauma).Trauma (tight shoes, nail biting).Poor foot care.Eczema (irritant or allergic contact dermatitis).Lichen planus.Subungual melanoma.Raynaud's phenomenonBacterial paronychia - eg, Pseudomonas spp. infection.Systemic disease - eg, thyroid disease, diabetes, peripheral arterial

disease.

InvestigationsNail material should be sent for microscopy. There is a

high false negative rate (30-40%)Culture of nail material should also be undertaken, as

this increases sensitivity and will determine species but may take several weeks.

Nail histology is not usually necessary unless there is reason to suspect another cause of nail pathology, such as psoriasis.

Polymerase chain reaction is an effective method of detecting dermatophytes but is not used in routine practice.

Interpretation of resultsMicroscopy results take a few days but culture results may

take 4-6 weeks. The results are regarded as positive

Associated diseasesDiabetes mellitusAny cause of immunocompromiseRaynaud's phenomenonPeripheral arterial diseaseTinea pedisOccupational dermatitis of handsPsoriasisNail trauma

How to recognize Nail Fungus?Nail fungus is made up of tiny organisms (Tinea Unguium) that can infect fingernails and toenails. The nails of our fingers and toes are very effective barriers. This barrier makes it quite difficult for a superficial infection to invade the nail. Once an infection has set up residence however, the same barrier that was so effective in protecting us against infection now works against us, making it difficult to treat the infection.

Is Nail Fungus contagious?Yes, it can be. The organisms can sometimes spread from

one person to another because these critters can live where the air is often moist

This can happen in places like shower stalls, bathrooms, or locker rooms or it can be passed around on a nail file or emery board. So, don't share them.

Nail fungus may also spread from one of your nails to other nails.

Nail Fungus: Treatment & Prevention.The best treatment of course is prevention. Keep your nails cut straight across. If nails are

hard to cut, soften by soaking in salt water (use 1 teaspoon per gallon of water and then dry well).

Keep feet dry and well ventilated. Be careful with artificial nails and be selective

about choosing your manicurist. Ask about how they sterilize their instruments. See a podiatrist or your health care provider if you see signs of fungus.

Management

Cosmetic treatment

Medical treatment

Surgical treatment

Cosmetic treatmentReferral to a chiropodist may be helpful.Nail filing and nail polish can lessen cosmetic

effects.It is helpful to trim dystrophic nails.In DLSO, remove nail and hyperkeratotic nail bed

with clippers.In SWO debride abnormal nail with a curette.

Medical treatmentTopical therapy

They should be reserved for mild distal disease in up to two nails, cases of SWO or where there are contra-indications to systemic therapy.

Treatment should be given daily for six months to one year.Can be used in cases of SWO or early DLSO where infection is confined to

the distal edge of the nail.5% amorolfine is effective and appears to be the best topical agent in terms of

its ability to penetrate the nail matrix. 28% tioconazole is also available but the evidence base for its effectiveness is

weak.Newer topical therapies such as tavaborole, efinaconazole and luliconazole

are being explored.Evidence for combination treatment with oral and topical antifungals is weak

and not currently recommended.

Systemic therapy:

Systemic treatment is recommended for most people, as it is more effective. The slow growth of nails means that they do not appear normal even after effective treatment.

TerbinafineCurrently first-line with evidence of greater

efficacy compared to itraconazole.ItraconazoleGriseofulvin

Side-effects of systemic antifungals headache itchingloss of sensation of tastegastrointestinal symptoms rash fatigue abnormal liver function.

SurgeryNail avulsion, removal of nail plate,

chemical treatments (eg, 40-50% urea solution for very thickened nails) and matrixectomy may enhance the effectiveness of oral treatment.

ComplicationsPoor cosmetic appearance of hands/feet.Disfigurement and total destruction of the nail plate.Paronychia.Damage to diabetic feet.Cellulitis, osteomyelitis, sepsis and necrosis in elderly

patients and people with diabetes.Psychosocial problems due to embarrassment at

cosmetic appearance.Pain and limitation of function, particularly in older

patients.

PrognosisThe prognosis is variable and depends on the

type of infection as well as host factors such as comorbidities and age.

Fingernail infections usually have much higher cure rates 70%.

Untreated, fungal nail disease is usually progressive, leading to gradual destruction of the nail plate.

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