Shedding Light on Onychomadesis
Onychomadesis is the proximal separation of the nail plate from the nail matrix due to a temporary cessation of nail growth. It can occur in children of all ages including neonates. Diagnosis is made clinically through palpation and inspection of the nail plate. Physicians should consider underlying associations. A review of the patient’s history for any viral illnesses 1 to 2 months prior to nail changes often will help identify the causative disease. Onychomadesis typically is mild and self-limited. There is no specific treatment, but a conservative approach to management is recommended with treatment of any underlying causes and supportive care. Spontaneous nail regrowth usually occurs within 12 weeks and may occur faster in children. In this article, causes of onychomadesis are described, including the connection between hand-foot-and-mouth disease (HFMD) and onychomadesis. We also explore several theories of possible mechanisms for onychomadesis; however, the precise mechanism remains unclear and further investigation is needed.
Practice Points
- Onychomadesis in a child may be a cutaneous sign of systemic disease.
- In childhood, onychomadesis is sometimes linked with hand-foot-and-mouth disease.
- Spontaneous nail regrowth usually occurs within 12 weeks but may occur faster in children.
Clinical Characteristics
The ventral floor is the site of the germinal matrix and is responsible for 90% of nail production. As a result, more of the nail plate substance is produced proximally, leading to a natural convex curvature from the proximal to distal nail.11 Beau lines are transverse ridging of the nail plates.6 Onychomadesis may be viewed as a more severe form of Beau lines, with complete separation and possible shedding of the nail plate (Figure).3,4 In both cases, an insult to the nail matrix is followed by recovery and production of the nail plate at the nail matrix.4 In Beau lines, slowing or disruption of cell growth from the proximal matrix results in a thinner nail plate, leading to transverse depressions. Onychomadesis has a similar pathophysiology but is associated with a complete halt in the nail plate production.3
Diagnosis
The diagnosis of onychomadesis is made clinically.3,10 Distinct nail changes can be detected by inspection and palpation of the nail plate,3,11 which allows for differentiation between Beau lines and complete nail shedding. Additionally, any signs of nail trauma need to be noted, as well as pain, swelling, or pruritus, as these symptoms also can guide in determining the etiology of the nail dystrophy. Ultrasonography can confirm the diagnosis, as the defect can be identified beneath the proximal nail fold.3,26 When it occurs after HFMD or varicella, onychomadesis tends to present in 28 to 40 days following infection.4,6,10 Physicians should consider underlying associations. A review of viral illnesses within 1 to 2 months prior to development of nail changes often will identify the causative disease.4 Each patient should be evaluated for recent nail trauma; medications; viral infection; and autoimmune, systemic, and inflammatory diseases.
Treatment
Onychomadesis typically is mild and self-limited.4,10 There is no specific treatment,10 but a conservative approach to management is recommended. Treatment of any underlying medical conditions or discontinuation of an offending medication may help to prevent recurrent onychomadesis.3 Supportive care along with protection of the nail bed by maintaining short nails and using adhesive bandages over the affected nails to avoid snagging the nail or ripping off the partially attached nails is recommended.4 In some cases, onychomadesis has been treated with topical application of urea cream 40% under occlusion27 or halcinonide cream 0.1% under occlusion for 5 to 6 days,28 but these treatments have not been universally effective.3 External use of basic fibroblast growth factor to stimulate new regrowth of the nail plate has been advocated.3 It is important to reassure patients that as long as the underlying causes are eliminated and the nail matrix has not been permanently scarred, the nails should grow back within 12 weeks or sooner in children. Thus, typically only reassurance and counseling of parents/guardians is required for onychomadesis in children.1,2 However, the nails may be dystrophic or fail to regrow if there is poor peripheral circulation or permanent nail matrix damage.
Conclusion
Fortunately, onychomadesis is self-limited. Physicians should look for underlying causes of onychomadesis, including a history of viral infections such as HFMD and varicella as well as systemic diseases and use of medications. As long as any underlying disorder or condition has been resolved, spontaneous regrowth of healthy nails usually but not always occurs within 12 weeks or sooner in children.
