Nail Disorders
Nail disorders are common and range from onycholysis (separation of the distal nail from the underlying nail plate, usually with nail thickening and subungual debris), to nail pitting, to paronychia (an abscess next to the nail plate that can be very painful). Various focal, skin, or systemic disorders must be considered in all cases, thus requiring a focused yet complete evaluation of the patient.
Differential Diagnosis
- Onychomycosis
–Very common cause of nail thickening,
yellowing, and subungual debris
–Due to a dermatophyte infection
–May affect one or all fingers and toenails
–Patients often have coexisting tinea pedis or
tinea manum
- Psoriasis
–More than 50% of patients with psoriasis have associated nail changes, including pits, “oil spots,” and onycholysis
–Distinguishing nail fungus from psoriasis can be very difficult on clinical exam
–Most patients with nail disease have some other skin manifestation of psoriasis (plaques of thick, silvery white, adherent scalp scale that overlies well-demarcated patches of erythema)
- Paronychia
–Tenderness, erythema, and peeling around
the nail
–Very common and exquisitely painful
–Often exacerbated by “wet-work” (e.g.,
dishwasher)
–May have bacterial and/or yeast (candida)
component
–Occurs after minor cuticular trauma
–Can cause nail dystrophy without treatment
- Nail trauma
–Very common, especially great toenails and
thumbnails
–Easily misdiagnosed as fungal disease
–Can cause separation of the nail from the
nail plate
-
Malignancy (e.g., subungual melanoma, squamous cell carcinoma)
-
Endocrine disease (e.g., hyper- and hypothyroidism) can cause splitting, drying, and other nail changes
-
Lichen planus and atopic eczema can affect the nail matrix and lead to nail dystrophy
-
Alopecia areata (patchy autoimmune hair loss) can be associated with nail pits as well
-
Several congenital disorders (e.g., ectodermal dysplasia) can cause nail dystrophy in association with other skin and systemic disorders
-
Spoon-shaped nails may indicate iron deficiency
Workup and Diagnosis
-
History and physical examination
–Personal or family history of psoriasis
–Full skin exam to assess for skin disease
–Ask about the patient's work and hobbies
-
Onychomycosis (nail fungus) is diagnosed by clipping the affected nail and curetting subungual debris for PAS (fungal stain) and/or culture
–PAS stain is less expensive and quicker than culture
–Cultures are more helpful when a patient is refractory to systemic therapy; certain nondermatophytes (e.g., Aspergillus, Fusarium) can act as nail pathogens and are difficult to eradicate with some antifungal drugs
-
Paronychia requires incision and drainage for fungal and bacterial cultures to determine the appropriate topical or systemic treatment and to relieve pain
-
Nail matrix biopsy is unnecessary unless a tumor may be the cause of a persistent, isolated, single nail dystrophy or deeply pigmented longitudinal band (>3 mm)
-
Referral to dermatology is indicated in unusual, recalcitrant, or potentially malignant cases
Treatment
- Nail fungus can be treated with systemic antifungals (e.g., terbenafine, itraconazole, fluconazole)
–Fingernail fungus often requires 6 weeks of systemic therapy, whereas toenail fungus requires 12 weeks of treatment to achieve a 70–80% cure rate
–No absolute indication to treat nail fungus; if the patient is diabetic, nail fungus can compromise the integrity of the nail bed, thereby allowing bacterial pathogens to enter that may lead to extremity cellulitis
–Topical paint-on ciclopirox has low success rate (17%)
–Educate the patient that the risk of recurrence of onychomycosis is very high; modify lifestyles to prevent reinfection (antifungal powders on feet/shoes)
-
Intralesional steroids in the nail matrix are very painful but offer long-term improvement in nail dystrophy due to lichen planus, psoriasis, atopic eczema
-
Nail psoriasis may be treated topically with limited success; systemic antipsoriatic therapies (e.g., cyclosporine, methotrexate) are also used
Book Source Details
- Book Title: In a Page: Signs and Symptoms
- Author(s): Scott Kahan, Ellen G. Smith
- Year of Publication: 2004
- Copyright Details: In a Page: Signs and Symptoms, Copyright © 2004 Lippincott Williams & Wilkins.
Other Book Chapters Related to Fingernail symptoms
Read excerpts from these other book chapters related to Fingernail symptoms:
Copyright Details: In a Page: Signs and Symptoms, Copyright © 2008 Williams & Wilkins.
More About Causes of Fingernail symptoms
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More About This Book:
Title: In a Page: Signs and Symptoms
Authors: Scott Kahan, Ellen G. Smith
Publisher: Lippincott Williams & Wilkins
Copyright: 2004
ISBN: 1-4051-0368-X
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» Next page: NAIL CHANGES (Differential Diagnosis in Primary Care)
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