Chapter 14: Onycholysis

SUMMARY

• Onycholysis is a common medical condition characterized by detachment of the nail plate from the underlying nail bed due to disruption of the onychodermal band.

• Causes of onycholysis are multifaceted and can be related to exogenous, endogenous, genetic, or idiopathic factors.

• Management of onycholysis, though generally a self-limited condition, is centered around identifying and addressing the predisposing condition.

TIPS FOR DIAGNOSIS

• Clinicians should obtain a thorough history that includes information about the onset of the onycholysis, characteristic features, past medical history, and social history that encompasses occupation, grooming habits, and exposures to chemicals or irritants.

• Diagnosis of onycholysis is facilitated by careful examination through onychoscopy (nail dermoscopy), which can help to identify features suggestive of certain etiologies.

• Onycholysis that affects multiple or all nails is more likely to be related to systemic causes, whereas onycholysis that affects only one nail may be suggestive of tumors, trauma, or infection.

• Assess for other nail signs and consider nail psoriasis when onycholysis is surrounded by an erythematous border.

• Look for podiatric abnormalities in toenail onycholysis.

TIPS FOR TREATMENT

• Given the wide range of potential causes of onycholysis, treatment is centered around identifying and addressing the underlying cause.

• Topical antiseptic solutions (e.g., thymol 3%–4% in chloroform or in 95% ethanol) and/or topical antifungals (e.g., ciclopirox 0.77%) may be applied to the nail beds.

DON’T FORGET

• Onycholysis can occur in any nail on the hands or feet and may involve one or multiple nails.

• In onycholysis, the lytic portion of the nail appears white or opaque, which can be distinguished from the normally pink nail.

• Although onycholysis can affect both sexes and all age ranges, it preferentially affects females and adults.

PITFALLS AND CAUTIONS

• Leukonychia, or whitening of the nail, may appear similar to onycholysis and should be ruled out.

• Although Pseudomonas aeruginosa and Candida albicans are frequently cultured from the onycholytic space, studies have suggested there may be limited to no clinical benefit in treating these cases with antibiotics and antifungals.

EXPERT PEARLS

• Workup includes obtaining a detailed history with attention to timeline, examining all the nails of the hands and feet, conducting a full skin exam, and ordering laboratory tests based on clinical suspicion of systemic causes.

• Nail scrapings may be obtained for bacterial or fungal culture. Diagnosis may be further aided by ultrasound, MRI, or X-ray.

PATIENT EDUCATION POINTS

• Most cases of onycholysis, which generally present as gradual and painless separation of the nail from the nail bed, resolve spontaneously in a matter of months as new nail regrows.

• Measures to prevent onycholysis include keeping the nails short to minimize potential traumas, avoiding exposures to chemical irritants until the new nail has regrown, and avoiding high-heeled or narrow-toed shoes.

• Patients should trim the portion of detached nail every 2 weeks to prevent it from catching on any surroundings, but mechanical cleaning ...