History

Fact Explanation
Slow and insidious history of discoloration of the free edge of the nail. Tinea unguium is a infection of the nail with dermatophytic fungi. Dermatophytes most often infect the distal nail bed and under surface of the distal nail. The most common etiologic species are Trychophyton rubrum and Trychophyton mentagrophytes. [1],[2],[3],[6]
Crumbly nails. Affected nails easily breaks in to small pieces, especially at the edges. Fungal keratinases disrupt the keratin structure of the plate. [1],[2],[3]
Deformity of the nails. Fungal keratinases which disrupt the keratin structure of the plate facilitates deformity of the nail.[1],[2],[3]
Difficulty in nail trimming. Due to crumbly nature, deformation and thickening may cause difficulty in nail trimming. [1],[2],[3]
Discomfort of wearing shoes. It may cause pain of the affected nail. Pain and deformity of the nail may cause discomfort of wearing shoes. [1]
History of immuno suppression. Protection against fungal infection is produced by cell mediated immunity. HIV infection, Long term steroid therapy, Cushings syndrome and immuno deficient disorders may be possible in the the history. [1],[4],[5]
Contact history Contact history of affected family member, communal bathing, occupational history of contact with animals and trauma are possible risk factors in the history. [1],[2],[3]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.
  4. QADIM, H.H. GOLFOROUSHAN, F. AZIMI, H. and Goldust, M. Factors leading to dermatophytosis. [Online]Annals of parasitology. 2013;59(2):99-102. [Viewed on 23.04.2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/24171304
  5. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.
  6. LONE, Rubeena. BASHIR, Deeba and KHURSHID, Syed. A Study on Clinico-Mycological Profile, Aetiological Agents and Diagnosis of Onychomycosis at a Government Medical College Hospital in Kashmir. [Online] Journal of Clinical and Diagnostic Research. Sep 10, 2013. [Viewed 0n 23.04.2014] Available from doi: 10.7860/JCDR/2013/5969.3378

Examination

Fact Explanation
Discoloration the free edge of the nail. Dermatophytes most often infect the distal end of the nail which resulting discoloration (White, Yellow or Brown) of the nail plate. Therefore initially affects the free edge of the nail. [1],[2],[3],[4]
Onycholysis. Due to subungal hyperkeratosis and accumulation of subungal debris results separation of the nail from its bed, starting at its distal and/or lateral attachment. [1],[2],[3]
Affected nails are deformed. Fungal keratinases which disrupts the keratin structure facilitates the deformity of the nail. [1]
Affected nails are thickened. Initially nails are crumble. but subungal hyperkeratosis results thickening of the nail. [1]
More common in toe nails. Infection of toe nails is more common than infection of finger nails, and it is uncommon for for all ten nails to be involved. [1],[2],[3],[5],[6]
Associated with Tinea pedis and Tinea mannum. Superficial fungal infection of the nail is probably a direct extension of involvement of surrounding digital skin. [1],[2],[3]
Affected proximal nail plate. Infection of the proximal nail plate is a marker of immuno suppression and must look specifically for the signs of immune deficient conditions such as HIV infection. [1]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.
  4. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.
  5. BANU, Asima. ANAND, Mridu and ESWARI, L. A rare case of onychomycosis in all 10 fingers of an immunocompetent patient, [Online], Indian Dermatol Online J.. 2013 Oct-Dec; 4(4): 302–304. [Viewed on 24.04.2014]. Available from doi: 10.4103/2229-5178.120649
  6. GELOTAR, Prakash. VACHCHANI, Swati. PATEL, Bhargav and Makwana, Naresh. The Prevalence of Fungi in Fingernail Onychomycosis. [Online] J Clin Diagn Res. Feb 2013; 7(2): 250–252. Dec 24, 2012. [Viwed on 24.04.2014] Available from doi: 10.7860/JCDR/2013/5257.2739

Differential Diagnoses

Fact Explanation
Psoriasis Psoriasis Characteristically cause 'Thimble pitting' of the finger nails. It also causes well-defined pink/brown areas and onycholysis. The toe nails rarely show these changes. Usually associated with cutaneous psoriasis.[1],[2],[3],[4]
Eczema of the digits Their may be a history of irritant contact dermatitis. Eczema affecting nails may cause irregular deformities of fingernails and marked horizontal ridging. [1],[2],[3]
Lichen planus Nail involvement is not very common. The nail plate may develop longitudinal ridging. In severe condition it may penetrate the nail. [1],[2],[3]
Trauma History of repeated mechanical trauma is suggestive of traumatic paronychia. Must look for signs of trauma in affected nails. [1],[2],[3]
Chronic paronychia Paronychia is the inflammation of the tissue at the sides of the nail. In chronic paronychia it is tender and pus may be expressed from the space between nail fold and the nail plate. [1],[2],[3]
Changes with aging Age related nail changes are common in elderly people with history of trauma and subungal debris collection. . [1],[2],[3]
Yellow nail syndrome This is a rare disorder. A blackish, yellow green discoloration is seen. The nail growth is slowed, nails are thickened and show increased curvature. [1],[2],[3]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 54-70, 248-252, 276-279.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 128-148, 278-279.
  4. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.

Investigations - for Diagnosis

Fact Explanation
Light microscopic examination. The nail clipping should be taken from the affected free edge of the nail. The specimens are cleared in pottassium hydroxide (KOH). Compared with the skin scrapings, more time must be allowed for the KOH to dissolve thin nail specimens. In microscopic examination branching hyphae and spores can be seen. Occassionaly a nail biopsy is needed to obtain a positive results. [1],[2],[3]
Culture Culture Should be carried out in a mycology or bacteriology laboratory. Transport medium is not necessary, and specimens can be sent in folded black paper and dry petri dish. The report may take as long as a month: microscopy is much quicker. [1],[2],[3]
Dermoscopy It is used to differentiate tinea unguium from traumatic onycholysis. Distal nail involvement of tinea unguium has a typical "aurora borealis" pattern. [1],[2],[3]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.

Investigations - Followup

Fact Explanation
Periodic monitoring Patients are given systemic antifungals for long term. Therefore must arrange out patient follow up visits to monitor for adverse events of medications such as hepatotoxicioty. Even with systemic therapy failure rate for toe nail infection are 20-30%. Recidual fungal spores present in the patients shoes and environment are probably responsible for recurrence of the infection. for this reason prophylactic topical antifungals are given when systemic therapy is over. [1],[2],[3]
Look for complications of the disease. Nearby skin injury may followed by risk of secondary bacterial infection. It may leads to cellulitis, osteomyelitis and septicemia. Threfore must examine patients carefully during follow up visits.[1]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.

Management - General Measures

Fact Explanation
Educate the patient. Tinea unguium is a common superficial fungal infection of the nail which can be treated successfully. But even with oral therapy failure rates for treating chronic toe nail infection are 20-30%. [1],[2],[3]
Advise regarding hygiene. Tinea unguium is considered as a contagious fungal infection and it has high recurrence rate. Therefore advise to keep their feet dry and clean and wear clean dry shoes, not to share shoes and socks of affected people and wear glouses and boots when handling soil and garbage . [1],[2],[3]
References
  1. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  2. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  3. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.

Management - Specific Treatments

Fact Explanation
Topical nail preparations Topical antifungal agents are considerd ineffective alone in treating tinea unguium because of their poor penetration of the nail plate. But a nail lacquer containing amorolfine is worth a trial for the patients who prefer to avoid systemic therapy. It should be applied once or twice a week for 6 months.Both amorolfine and ticonazole nail solutions can be used as adjunct to systemic therapy. Imidazoles interfere with fungal oxidative enzymes to cause lethal accumulation of hydrogen peroxide. They also reduce the formation of ergosterol, an important constituent of fungal cell wall which thus becomes permeable to intracellular constituents. [1], [2],[3],[4],[6]
Terbinafin It acts by inhibiting fungal squalaneepoxidase and does not interact with cytochrome p-450 system. It is fungicidal and so cures chronic dermatophyte infections more quickly and more reliably than griseofulvin. Treatment continue for finger nais for 6 weeks and for toe nails for 12 weeks. [1],[2],[3],[4],[5]
Itraconazole Is now preferred to Ketoconazole , which occasionally damages the liver, and is a reasonable alternative to terbinafin if this is contraindicated. Fungistactic rather than fungicidal, it interfere with cytochrome P-450 system, so a review of any other medication being taken is needed before a prescription is issued. Itraconazole 2 pulses given for fingernails and 3 pulses for toe nails. [1],[2],[3],[4]
Ketoconazole This drug should be reserved for patients with severe and resistant disease because of the possibility of serious hepatotoxicity and occurrence of other side effects, including rashes, Thrombocytopenia and gastrointestinal disturbances. [1],[2],[3],[4],[5]
Prophylaxis To prevent recurrence a topical antifungal such as ticonazole or miconazole applied to feet every week for long term prophylaxis. [1]
Lasers and photodynamic therapy Systemic antifungal medications are currently the treatment of choice. But treatment failure rate is high and oral therapy is contraindicated in some patients. Laser and photodynamic therapy may have the potential to treat onychomycosis locally without adverse systemic effects. But these therapies are expensive and time-consuming. [7]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. KATZUNG, Bertram G. MASTERS, Susan B. and TREVOR, Anthony J. Basic and Clinical Pharmacology. 12th Ed. Tata McGraw-Hill. 2012, 849-860.
  3. MARKS JR, James G. and MILLER, Jeffery. Lookingbill & Marks' Principles of Dermatology. 4th Ed. Elesvier. 2006,125, 275-277.
  4. BENNET, P.N. and BROWN, M.J. CLINICAL PHARMACOLOGY. 9th Ed. CHURCHILL LIVINGSTONE. 2003, 263-267.
  5. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 278-279.
  6. GUPTA, Aditya K. and SIMPSON, Fiona C. Efinaconazole: A New Topical Treatment for Onychomycosis, [Online] Skin Therapy Letter. 2014 Jan-Feb;19(1):1-4. [Viewed on 24.04.2014] Available from: http://www.skintherapyletter.com/2014/19.1/1.html
  7. Becker, Caitlin and Bershow, Andrea. Lasers and photodynamic therapy in the treatment of onychomycosis: a review of the literature. [Online]. Dermatology Online Journal. 19(9. 2013. [Viwed 24.04.2014] doj_19611. Available from:http://escholarship.org/uc/item/0js6z1kw