Fifth Disease and Hand, Foot, and Mouth Disease are common viral illnesses, often affecting children with rashes and other symptoms. Though they share some characteristics, these conditions are distinct, caused by different viruses, and have unique presentations. Understanding their differences aids identification and management, even though both typically resolve on their own.
Understanding Fifth Disease
Fifth Disease, also known as Erythema infectiosum or “slapped cheek disease,” is caused by human parvovirus B19. It spreads primarily through respiratory droplets. It is contagious, especially before the characteristic rash appears; individuals are generally no longer contagious once the rash develops.
Initial symptoms, often preceding the rash by several days, are mild and flu-like, including low-grade fever, headache, body aches, runny nose, and sore throat. The incubation period is usually 4 to 14 days. A bright red rash then emerges on the cheeks, giving the appearance of “slapped cheeks.”
Following the facial rash, a lacy, net-like rash may appear on the trunk, arms, and legs. This body rash can last for one to three weeks and may reappear with exposure to sunlight, heat, or exercise. While Fifth Disease primarily affects children aged 5 to 15, adults can also contract it. Adults may experience joint pain and swelling more frequently than children. Treatment is supportive, focusing on managing symptoms like fever and discomfort with over-the-counter medications.
Understanding Hand, Foot, and Mouth Disease
Hand, Foot, and Mouth Disease (HFMD) is a common viral infection caused mainly by coxsackievirus A16, though other enteroviruses can also be responsible. It spreads easily through direct contact with nasal secretions, saliva, blister fluid, or stool, and via contaminated surfaces or airborne droplets. People are most contagious during the first week of illness, even before symptoms fully emerge.
Symptoms typically begin 3 to 6 days after exposure, starting with fever, sore throat, and reduced appetite. Painful mouth sores usually develop one to two days later, affecting the tongue, gums, and inside of the cheeks. A characteristic rash then appears on the hands and feet, sometimes extending to the buttocks or knees. The rash consists of small red spots that can evolve into blisters.
HFMD is most common in infants and young children under five. While generally mild, mouth sores can make eating and drinking painful, potentially leading to dehydration. The illness usually resolves on its own within 7 to 10 days. Treatment focuses on supportive care, including adequate fluid intake and pain relievers for discomfort.
Key Distinctions Between the Conditions
The primary distinctions between Fifth Disease and Hand, Foot, and Mouth Disease lie in their causative viruses, rash characteristics, and transmission patterns.
Fifth Disease is caused by parvovirus B19, while HFMD is primarily due to coxsackievirus A16 and other enteroviruses. Fifth Disease features a “slapped cheek” facial rash and a lacy body rash, which typically does not blister or affect palms/soles. HFMD, conversely, presents with small, often painful blisters and red spots primarily on the hands, feet, and inside the mouth, with prominent mouth sores.
While both spread via respiratory droplets, HFMD also transmits through blister fluid and stool, unlike Fifth Disease. The contagious period also differs: Fifth Disease is most contagious before the rash, while HFMD is highly contagious during the first week of illness. Adults with Fifth Disease often experience joint pain, a symptom less common in HFMD.
When to Seek Medical Attention and Care
Both Fifth Disease and Hand, Foot, and Mouth Disease are typically mild and self-limiting, resolving with supportive home care including rest and adequate fluid intake. Over-the-counter medications can help manage fever and discomfort. Avoid aspirin for children or teenagers due to Reye syndrome risk.
Seek medical attention if symptoms worsen or complications arise. Consult a healthcare provider if a high fever persists over three days, or if there are signs of dehydration (e.g., decreased urination, dry mouth). Urgent signs requiring immediate medical evaluation include severe headaches, neck stiffness, extreme lethargy, difficulty breathing, or seizures.
Pregnant individuals exposed to Fifth Disease have specific concerns. If a pregnant woman develops a rash or joint pain after exposure, she should contact her healthcare provider. While most parvovirus B19 infections during pregnancy do not harm the fetus, a small risk of complications, including fetal anemia, exists, especially in the first 20 weeks. Healthcare providers can assess and recommend monitoring.