HFMD and Kidney Troubles: What Parents Need to Know
"Understanding the Link Between Hand, Foot, and Mouth Disease and Acute Kidney Injury in Children"
Hand, Foot, and Mouth Disease (HFMD) is a viral infection that causes sores in the mouth and a rash on the hands and feet and is common in children. Most cases are mild, but a recent study has highlighted a concerning link between severe HFMD and acute kidney injury (AKI). AKI is when the kidneys suddenly can't filter waste from the blood, leading to a buildup of toxins and potential health problems.
The typical causes of pediatric AKI include infections, kidney or urinary tract problems, dehydration, and certain medications. A study in China found that infectious diseases accounted for a significant portion of AKI cases in children. HFMD, primarily caused by enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16), is a common culprit behind childhood infections, raising concerns about the potential kidney complications.
While HFMD is usually associated with fever, rash, and discomfort, it's crucial for parents to be aware of the possibility of kidney involvement. Recognizing the signs and understanding the connection can lead to prompt medical attention and better outcomes for your child. A research highlights a case where a child with EV-A71-associated HFMD developed AKI, emphasizing the importance of vigilance.
HFMD’s Current Burden
Hand-foot-and-mouth disease (HFMD) is a viral illness commonly seen in children under 5, with oral lesions and rashes on the hands and feet that typically resolve spontaneously. It is caused by more than 20 enterovirus serotypes, and in China it has been on the List of Quarantinable Diseases since May 2, 2008. Chinese Center for Disease Prevention and Control data identify HFMD as the country’s second most reported infectious disease. In the United States, reported annual HFMD mortality from 2018 through 2025 was typically 0–3 deaths per year based on ICD-10 code B08.4 tracking.
Diagnosis and Testing
HFMD diagnosis commonly begins with a physical examination, while laboratory methods can identify the responsible enterovirus. The most common causative agents include enterovirus 71 (EV71) and coxsackievirus A16 (CVA16), with EV71 more associated with fatalities from severe neurological disorders. Molecular approaches described in the literature include real-time PCR, nested RT-PCR, and loop-mediated isothermal amplification. Recent research has focused on isothermal nucleic acid amplification techniques because rapid point-of-care testing may support timely identification and outbreak prevention.
A Modern Medical History
Human HFMD has been formally known since 1957, unlike animal foot-and-mouth disease, which has been recognized for centuries. Clinical observations of HFMD were later followed by virological confirmation in New Zealand in 1957. That confirmation marked the beginning of the disease’s formal study and helped distinguish the human illness from the similarly named animal disease.
What are the Symptoms of Kidney Problems Related to HFMD?
In addition to the typical symptoms of HFMD, such as fever, mouth sores, and rash, watch out for these signs that could indicate kidney involvement:
- Decreased urine output
- Swelling, especially around the eyes, face, hands, or feet
- High blood pressure
- Fatigue or lethargy
- Changes in urine color (darker or tea-colored)
What Recent Research Shows
A narrative review reports that HFMD is usually benign and resolves within 7 to 10 days without sequelae. Kidney complications appear uncommon in the available literature: renal failure has been reported in two HFMD cases associated with CV-A16, and one case of acute kidney injury was reported after EV-A71 infection. Another study evaluated 25 children with enterovirus infection using KIM-1 alongside blood creatinine and estimated glomerular filtration rate to assess acute kidney injury.
Limits of the Evidence
Evidence linking HFMD with kidney involvement remains limited. One source states that, to date, only two case reports describe renal involvement as secondary to or coexisting with CV-A16-associated HFMD. Broader HFMD evidence is also geographically concentrated and methodologically narrow, which limits how confidently findings can be generalized. Although HFMD is typically self-limiting, some patients can rapidly develop severe complications involving the central nervous system or respiratory system.
Molecular Surveillance Examples
Laboratory surveillance studies have used real-time fluorescence RT-PCR to detect human enterovirus, EV71, and coxsackievirus A16 nucleic acids in 363 samples from HFMD patients in Dalian City in 2010. A separate Shenzhen surveillance study tested EV71 RNA by RT-PCR in 79 fecal samples from infants with HFMD. These studies illustrate a shared reliance on RT-PCR-based detection while differing in location, sample size, target pathogen coverage, and specimen type.
The Bottom Line: Staying Informed and Proactive
While the link between HFMD and AKI is rare, it's essential for parents to be aware of the potential risks. By knowing the symptoms, seeking prompt medical care, and following your doctor's recommendations, you can help protect your child's health and well-being. Stay informed, stay vigilant, and don't hesitate to ask questions – your child's health is always worth it.
Putting HFMD in Context
HFMD is a worldwide public health issue that commonly affects children 5 years of age or younger and is primarily caused by enteroviruses in the Picornaviridae family. A review of epidemiological studies found that China has the highest incidence, with May and June identified as peak months and younger age associated with higher risk of death. These patterns support treating kidney concerns as part of a broader assessment of possible severe disease rather than as the usual course of HFMD.
Why Severe Cases Matter
Severe HFMD caused by EV-A71 is associated with acute neurological disease in children. A systematic review examined the burden of long-term sequelae and death following severe HFMD. This focus on outcomes after severe disease shows why monitoring complications matters even though many HFMD infections are mild. The available source addresses neurological severity and long-term outcomes rather than establishing a general rate of kidney complications.