Hand-foot-mouth disease (atypical) B08.4

Worldwide occurring exanthematic infectious disease caused by Coxsackie A 6 and more rarely Coxsackie A 10.

The pathogens are not Coxsackie A 16 and Enterovirus 71 as in the classic hand-foot-and-mouth disease, but Coxsackie A6 virus and, more rarely, Coxsackie A10 virus. The transmission of the virus is faeco-oral.

In contrast to the typical age distribution of enterovirus infections, individual outbreaks often also affected adults (e.g. 25% in the USA). A hand-foot-mouth disease in adults is rather rare due to the high infestation in childhood! If adults are affected, this may indicate an immunological naivety of these adults towards the currently circulating Coxsackie-A6 virus strain.

face, extremities, trunk buttocks

Polymorphic exanthema with papules, vesicles, blisters and erosions. After 3 weeks the appearance of onycholysis is characteristic. In individual outbreaks there was a severe clinical expression of the symptoms with perioral and perianal vesicles, high fever and subsequent onycholysis. Multiple intrafamily virus transmissions from children to parents have also been detected.

From smears from vesicles or erosions detection of the pathogen by RT-PCR on Coxsackie-A6.

Further diagnostics for molecular typing includes PCR in the protein-coding VP1 region with subsequent sequencing (reference laboratory). Stool samples, throat swabs and vesicle contents are best suited for the detection of enteroviruses. In case of CNS manifestation, CSF can also be examined. Approximately 80 % of the pathogens can be detected from the stool in the first 1-2 weeks of the disease.

Hand-Foot-Mouth Disease (classic)

contagious impetigo

Gianotti-Crosti syndrome

Varicella

Symptomatic

The risk of infection can be reduced by good hand hygiene:

• Regular and careful hand washing with soap, especially after nappies and after going to the toilet, plays a crucial role.
• Dirty surfaces and objects (including toys and door handles) must be cleaned particularly thoroughly in accordance with the hygiene plan of public institutions.
• Close contact with sick people should be avoided (kissing, hugging, sharing cutlery or cups etc.).

The serotype Coxsackievirus A6 is primarily associated with the clinical picture of herpangina. It has been associated with outbreaks of hand-foot-and-mouth disease in Finland in 2008, France and Taiwan in 2010, Japan in 2011, USA in 2012.

Since the Hand-Foot-Mouth Disease is not subject to notification according to the German Protection against Infection Act (IfSG) and virological diagnostics are not usually performed, there are no valid epidemiological data on Hand-Foot-Mouth Disease in Germany.

1. Cisterna DM et al (2019) Atypical hand, foot, and mouth disease caused by Coxsackievirus A6 in Argentina in 2015 Rev Argent Microbiol 51:140-143.
2. Hoffmann AJ et al. (2020) Atypical hand-foot-and-mouth disease. CMAJ. 192: E69.
3. Horsten HH et al (2018) Atypical Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6 in Denmark: A Diagnostic Mimicker. Acta Derm Venereol 98:350-354.
4. Merzel Šabović EK et al (2019) Atypical hand, foot, and mouth disease in an adult patient: a case report and literature review. Acta Dermatovenerol Alp Pannonica Adriat 28:85-88.