Coxsackie Virus (Hand, Foot, and Mouth Disease) in Baby
The short answer
Coxsackie virus is the most common cause of hand, foot, and mouth disease (HFMD) in children. It causes fever, painful mouth sores (small ulcers on the tongue, gums, and inside of cheeks), and a blister-like rash on the hands, feet, and sometimes buttocks. It is extremely common in children under 5 and spreads easily in daycare settings. There is no specific treatment - it is a viral illness that resolves on its own within 7-10 days. The main concern is ensuring your child stays hydrated, as the mouth sores can make eating and drinking painful.
Parents everywhere have the same worry. You are doing the right thing by looking into it.
By Age
What to expect by age
0-12 months
Babies with coxsackie virus often present with fever, irritability, drooling (from mouth sores), and refusal to feed. The rash may appear as small blisters on the palms, soles, and buttocks. Babies are at higher risk for dehydration because the mouth sores make feeding painful. Offer small, frequent feeds of breast milk, formula, or an electrolyte solution. Cold liquids and popsicles (for babies eating solids) can help soothe the pain. Avoid acidic or salty foods. The illness is most contagious in the first week, especially while the child has a fever.
1-3 years
Hand, foot, and mouth disease is very common in toddlers, especially those in daycare. After a 3-5 day incubation period, the illness starts with fever, sore throat, and reduced appetite, followed by mouth sores and the characteristic rash. The rash may also appear on the knees, elbows, and buttocks. Treatment is supportive: acetaminophen or ibuprofen for pain and fever, cold fluids and popsicles for mouth soreness, and avoiding spicy or acidic foods. Blisters are not typically itchy. Peeling of finger and toenails (onychomadesis) can occur 4-8 weeks later and is harmless. Children can return to daycare after the fever resolves, though they remain mildly contagious for weeks through stool.
What Should You Do?
When to take action
- Fever lasting 2-3 days
- Mouth sores that are painful but improving over 5-7 days
- A blister-like rash on hands, feet, and/or buttocks
- Reduced appetite for a few days due to mouth soreness
- Nail peeling 4-8 weeks after the illness (harmless)
- Your child is not drinking enough fluids due to mouth sore pain
- The fever lasts more than 3 days
- You want to confirm the diagnosis
- Your child has had HFMD symptoms for more than 10 days without improvement
- Signs of dehydration: no wet diaper for 6+ hours, no tears when crying, dry mouth, sunken eyes
- High fever above 104 degrees F (40 degrees C)
- Your child is lethargic, not just tired
- A newborn (under 1 month) with symptoms of HFMD
- Severe headache with stiff neck and fever (rare complication - viral meningitis)
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
Related Medical Concerns
Hand, Foot, and Mouth Disease in Babies
Hand, foot, and mouth disease (HFMD) is a very common viral illness in babies and toddlers, especially during summer and fall. It causes small blisters or sores in the mouth and a spotted rash on the hands and feet. While it can make your child uncomfortable for a few days, it is not dangerous and resolves on its own within 7-10 days.
Hand, Foot, and Mouth Disease - How Long Is It Contagious?
Hand, foot, and mouth disease (HFMD) is most contagious during the first week of illness, particularly in the first few days when the child has a fever. However, the virus can be shed in stool for weeks after symptoms resolve. The incubation period is 3-5 days (time from exposure to symptom onset). Most daycare and school policies allow children to return once the fever is gone for 24 hours and they can participate in activities. You cannot fully prevent spread once a child is symptomatic, as they were most contagious before anyone knew they were sick.
Herpetic Gingivostomatitis (Mouth Sores) in Babies
Herpetic gingivostomatitis is a common first-time infection with the herpes simplex virus (HSV-1) that causes painful sores on the gums, tongue, lips, and inside the cheeks. It is most common in children between 6 months and 5 years. While the sores look alarming and can make eating very painful for several days, the infection resolves on its own within 7-14 days. The main concern is keeping your child hydrated while their mouth is sore.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.