​Kembara Xtra - Medicine - Onychomycosis

​Kembara Xtra - Medicine - Onychomycosis 
Fingernail/toenail fungal infection — mostly caused by dermatophytes, but also by yeasts and nondermatophyte molds It affects toenails more frequently than fingernails.
 Alternative: tinea unguium

Epidemiology 
Prevalence Occurs in 2-10% of the general population Predominant age: 20% in adults >60 years old, 50% in adults >70 years old Rare before puberty Prevalence 15-40% in people with HIBI Estimated 50% of all nail abnormalities in the outpatient setting

Pathophysiology and Etiology 
Dermatophytes include Trichophyton (most commonly Trichophyton rubrum), Epidermophyton, and Microsporum. Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei are the four most prevalent yeasts. Molds include Cephalosporium, Hendersonula toruloidea, Alternaria tenuis, Scopulariopsis brevicaulis, and Aspergillus species.
90% of toenail and the majority of fingernail onychomycoses are brought on by dermatophytes.
Yeasts, particularly Candida, may affect fingernails or toenails (this happens frequently). Dermatophytes can invade healthy keratin, but nondermatophyte molds enter altered keratin (such as that found in damaged or dystrophic nails).

Older age, tinnitus, clunky shoes, cancer, diabetes, psoriasis, peripheral vascular disease, cohabitation with people who have onychomycosis, immunodeficiency, communal swimming pools, history of nail trauma, and autosomal dominant genetic predisposition are risk factors.


Keeping feet cool and dry, avoiding occlusive footwear, wearing sandals in public restrooms and swimming pools, and discarding or treating infected socks and shoes are all general preventative measures.

Associated Conditions Tinea pedis/manuum Immunodeficiency/chronic metabolic disorder (ex., diabetes)

Evaluation Clinical Diagnosis 
80% of dermatophyte infections involve toenails, particularly the hallux; simultaneous infection of fingernails and toenails is uncommon. Dermatophytes: Frequently preceded by dermatophyte infection at another site. There are five clinical forms: - The most prevalent onychomycosis is distal/lateral subungual, which is mostly caused by T. rubrum.
Spreads from the distal/lateral edges to the nail bed and nail plate; subungual hyperkeratosis; onycholysis; nail dystrophy; coloring that is either yellow-white or brown-black, known as bois vermoulu (literally, "worm-eaten wood"); onychomadesis Leukonychia—begins at proximal part of nail plate, appearing to occur from the proximal underside of the nail (or direct invasion of the nail plate from above); spreads to nail plate and lunula; seen with immunosuppressive conditions—proximal subungual onychomycosis (rare; 1% of cases): hands/feet 10% of cases of superficial (formerly known as superficial white onychomycosis): Trichophyton mentagrophytes is most frequently to blame for an infection of the nail's outer surface, which manifests as merging opaque white patches on the nail plate that finally cover the entire nail surface. Endonyx onychomycosis affects the inside of the nail plate while sparing the nail bed. The nail turns milky white and develops indentations.
There is no subungual hyperkeratosis.
- Totally dystrophic onychomycosis results in a thicker, ridged nail bed covered with keratotic debris once the fungus completely destroys the nail plate.
70% of all candida nail infections occur on the hands, especially the dominant hand; the middle finger is the most commonly affected.
- Unless secondary infection, pain is minimal. increases with extended water contact begins with cuticle separation and results in white or white-yellow nail discolouration. - Mainly affects tissue around nail. - Onycholysis, especially on hands; secondary ungual changes: convex, uneven, striated nail plate with dull, rough surface. There could be distal subungual onychomycosis.
- Nail plate involvement is infrequent during the primary stage; the nail plate is thin, flaky, opaque, and brownish in color and distorted by transverse grooves.
- Periungual edema/erythema (club-shaped, enlarged fingertips) may develop.
Molds (nondermatophytes) are more prevalent in older people and in the hallux nails.
- Similar to lateral and distal onychomycosis

Child Safety Considerations
The U.S. Food and Drug Administration (FDA) has not approved any systemic antifungal medications for the treatment of onychomycosis in children, even though candidal infection manifests more frequently as superficial onychomycosis. Some systemic antifungals have efficacy and safety profiles in children that are comparable to those that have been previously documented in adults.


Multiple Diagnoses 

Lichen planus, Onychogryphosis (also known as "ram's horn nails"), Traumatic dystrophy, Psoriasis (the most frequent alternate diagnosis),
 Eczematous ailments
Low thyroid function
Drugs and other substances
Yellow nail disorder
Subungual neoplasms account for 0.7–3.5% of all melanoma cases. Consider subungual melanoma if dark pigment in a brownish-yellow nail extends into the periungual skin fold.
Chronic paronychia, Pemphigus vulgaris, and alopecia areata

Laboratory Results 

Laboratory and clinical evidence are both necessary for an accurate diagnosis. The range of diagnostic accuracy is 66% to 75%.
On visual inspection, about 50% of nail degeneration is not fungal in origin, hence laboratory testing increases diagnostic precision.
To diagnose proximal subungual onychomycosis, a nail plate biopsy or partial/complete excision of the nail with culture is required.

Initial examinations (lab, imaging)
Utilizing a nail sample prepared with potassium hydroxide (KOH) and direct microscopy Cultures: 30% of false-negative findings may take 3 to 6 weeks to appear.
 Limited research have been done on the in-office dermatophyte test, which shows dermatophyte growth with a yellow-to-red color change of the medium.  Periodic acid- Schiff (PAS) stain both the nail clippings and the nail plate punch biopsies for proximal lesions.
 Although not commonly available, polymerase chain reaction (PCR) boosts the sensitivity of detecting dermatophytes in nail specimens. Results are available in three days and can be utilized in addition to direct microscope examination and fungal culture. For the quick identification of fungus in nail specimens, fluorescence microscopy might be used.
Commercial labs may combine KOH and calcofluor white stain to enhance the visibility of fungi in fluorescence microscopy.
Before getting a sample, stop using any topical medications for at least a week.
Interpretation of Tests
pathogens in the keratin of the nail

Management Prevent the formation of fungi by avoiding conditions that do so (such as heat, wetness, occlusion, and tight-fitting shoes).
Treat the underlying causes of disease risk.
 Manage supplementary infections.

Pregnancy and Medication: Considerations
Pregnancy Category B (terbinafine, ciclopirox) or C (itraconazole, fluconazole, and griseofulvin) drugs include oral antifungals and ciclopirox. The teratogenicity and conjoined twin concerns associated with griseofulvin make it contraindicated during pregnancy. Onychomycosis should ideally be treated after pregnancy.
Initial Line
Oral antifungals are recommended because they have higher cure rates, but they also have significant drug-drug interactions and systemic side effects.
Terbinafine, 250 mg/day PO for 6 weeks for fingernails and 12 weeks for toenails, was found to be the most successful treatment for toenail onychomycosis in terms of both curing the condition and preventing relapse when compared to other antifungals and itraconazole pulse.Posaconazole, voriconazole, and itraconazole are among the alternative treatments for infections that are resistant to terbinafine.
Itraconazole pulse: 200 mg PO BID for 1 week, followed by 3 weeks off; repeat for 2 cycles for fingernails, and 3–4 cycles for toenails; pulse dose does not require monitoring of liver function tests (LFTs).  Itraconazole continuous: 200 mg/day PO for 6 weeks for fingernails and 12 weeks for toenails (less effective for dermatophytes than itraconazole pulse, more effective for Candida and molds than terbinafine).

Next Line
Fluconazole pulse is not FDA-approved for treating onychomycosis; 150 to 300 mg PO once a week for six months. Posaconazole: 100, 200, or 400 mg once day for 24 weeks; 400 mg once daily for 12 weeks; higher cost; Griseofulvin: 500 to 1,000 mg/day PO for up to 18 months Topical medications should only be used for conditions that do not affect the proximal nail plate (lunula). Although topical medication is not systemically harmful, it is significantly less effective than oral therapy.
 For 48 weeks, apply a 10% efinaconazole solution directly to the afflicted nails once daily; the cure rate is complete or almost complete at 15–18%.
Apply Ciclopirox, an 8% nail lacquer, once daily to the damaged nails (assuming there is no lunula involvement) for up to 48 weeks. After that, remove the lacquer with alcohol every 7 days, file away any loose nail material, and trim the nails.
Tavaborole 5% solution is indicated for onychomycosis of the toenails caused by T. rubrum or T. mentagrophytes; complete or nearly complete cure 15–18% after 48 weeks; contraindications for oral antifungals include hepatic disease. Application after PO treatment may reduce recurrences; systematic review >60% failure rate after 48 weeks of use.
- Maternity
- Ventricular dysfunction (itraconazole) - Porphyria (griseofulvin) - Current/history of congestive heart failure (CHF) - Warnings/side effects - Oral antifungals
Proteinuria (griseofulvin), lupus-like symptoms, hypersensitivity, photosensitivity, hepatotoxicity/neutropenia, chronic kidney disease (avoid terbinafine for patients with creatinine clearance [CrCl] 50 mL/min, reduce fluconazole dose), and photosensitivity. Itraconazole for CHF, pulmonary edema, and peripheral edema
Itraconazole for rhinitis
Topical ciclopirox side effects include rash and nail problems; prevent skin contact with the exception of the nail edge; use caution if you have damaged skin or vascular compromise; oral medications have a number of major drug-drug interactions; you should check each medication.

Nail débridement to remove infected keratin is a surgical procedure. Use if only a few nails are affected or, if not, for systemic therapy candidates.
- Mechanical: Use a curette or abrasive stone to file.
- Chemical: Apply an ointment containing 30% salicylic acid, 40% urea, or 50% potassium iodide under an occlusive dressing to protect peripheral tissue.
- Débridement and topical antifungal treatment are both options.
- Surgical avulsion for pain relief if only a few nails are involved
Although laser therapy has produced some encouraging outcomes, there is little evidence of its effectiveness or safety.
Keratolytic drugs such as urea, salicylic acid, and papain applied to the nail prior to topical medications have been proposed as agents that increase penetration of photodynamic therapy employing topical photosensitizing compounds and irradiation.

Alternative Therapies 

Tea tree oil, Melaleuca alternifolia: Cochrane review showed no evidence of benefit. Application of Vicks VapoRub to nails daily for 48 weeks has been deemed safe, but effectiveness is still debatable.

Take Action 
A new toenail takes 12 to 18 months to grow, compared to 4 to 6 months for a new fingernail.

Patient observation
 Terbinafine, griseofulvin: baseline, and as needed, LFTs and CBC Topical agents: Slow response is anticipated; visits every 6 to 12 weeks
 Continuous Itraconazole: baseline and LFTs as necessary

Keep the affected area dry and clean, stay out of occlusive shoes, use absorbent socks, throw away old sneakers, and refrain from sharing nail tools or using them on both infected and uninfected nails. There may not be a cure.

Oral therapy has a 25–50% complete clinical cure rate (higher mycologic cure rates) and a 10–50% recurrence rate (relapse/reinfection).
 Negative prognostic indicators
- Areas with >50% nail involvement
- Proximal/lateral illness that is significant
- White, yellow, or orange/brown streaks on the nail (including dermatophytoma) - Subungual hyperkeratosis >2 mm - Complete dystrophic onychomycosis (with involvement of the matrix)
- Nonresponsive organisms, such the mold Scytalidium - Individuals who are immunosuppressed
- Reduced peripheral vascularity


Complications include: Anxiety, low self-esteem; secondary infections that escalate to soft tissue infections or osteomyelitis; discomfort or pain in the toenails that might limit physical activity; and soft tissue infections or osteomyelitis.

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