Hand, Foot and Mouth Disease (HFMD) and Onychomadesis

 

Introduction

Nails are underutilized as diagnostic tools, despite being involved in many dermatologic conditions. This paper explores new concepts in the treatment of median nail dystrophy (MND), onychomycosis, and the nail pathology of hand, foot, and mouth disease (HFMD). A Pubmed database literature search was conducted for MND treatment, onychomycosis treatment, and HFMD nail pathology. Only papers published after January 2008 were reviewed. The results showed that 0.1% tacrolimus ointment can be an effective treatment for MND. Early studies on laser therapy indicate that it is a safe and efficacious treatment option for onychomycosis, compared to conventional oral antifungal agents. Vicks VapoRub (The Proctor & Gamble Company, Cincinnati, OH) is effective against onychomycosis and is a reasonable option in patients who choose to forgo conventional treatments. Lastly, there is evidence to support a correlation between HFMD and onychomadesis.

 

 Hand, Foot and Mouth Disease (HFMD) and onychomadesis

HFMD is usually caused by coxsackievirus A 16. Less commonly, it is caused by coxsackievirus A4, A5, A6, A7, A9, A10, A24, B2 to B5, enterovirus 71, and echoviruses.

All are RNA viruses and they spread by fecal-oral and respiratory routes. Spread to other family members commonly occurs.

HFMD is characterized by vesicular stomatitis and cutaneous lesions on the palms and soles. The disease has an incubation period of 3 to 6 days . There is usually a mild prodrome consisting of low-grade fever, anorexia, sore mouth, and malaise. Children younger than 10 years are most commonly affected. Oral lesions occur chiefly on the anterior buccal mucosa and tongue, where the vesicular surfaces are eroded rapidly, leaving ulcers with erythematous borders.

The lesions on the palms and soles are papules or vesicles on a surrounding zone of erythema. Less commonly, the dorsal or lateral surfaces of the hands and feet may also been affected. Involvement of the buttocks is common, but typically there is a lack of vesiculation.

The eruptions are nonpruritic and usually resolve without crusting. The association between HFMD and onychomadesis was first proposed by Clementz and Mancini in 2000 and Bernier et al. in 2001. Onychomadesis is the spontaneous separation of the nail plate from the matrix starting at the proximal edge and is the result of the temporary cessation of nail formation. Recently, authors in Spain and Finland have brought forth evidence to solidify the association between these conditions.

A study of an outbreak of HFMD in daycare centers and schools during the fall of 2008 in Finland led to one characteristic feature being found amongst the infected population: shedding of the nail plate approximately 1-2 months after the onset of classic HFMD symptoms. Redondo et al. documented a similar onychomadesis observation during an HFMD outbreak in Valencia, Spain in the winter of 2008. Fifteen children and one adult presented with nail changes consistent with onychomadesis, a mean of 6 weeks after the clinical diagnosis of HFMD. The nail changes were temporary with spontaneous normal regrowth in 1–4 months.

Clustered and sporadic HFMD cases, followed by onychomadesis (nail shedding), occurred during summer and fall 2008 in Valencia, Spain. Fecal samples from onychomadesis patients, who did or did not have previous HFMD, and from healthy children exposed to onychomadesis patients tested positive for EV.

The complete viral protein 1 capsid gene sequence was obtained for typing and phylogenetic analysis. Two EV serotypes, coxsackievirus A10 and coxsackievirus B1 (CVB1), were mainly detected as a monoinfection or co-infection in a childcare center where an onychomadesis outbreak occurred. On the basis of our results, and detection of CVB1 in 2 other contemporary onychomadesis outbreaks in childcare centers in Spain, we propose that mixed infection of an EV serotype that causes HFMD, plus the serotype CVB1, could explain the emergence after HFMD of onychomadesis, a rare and late complication.

Source:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3302018/

http://wwwnc.cdc.gov/eid/article/17/12/11-0395_article.htm