Lead
In the middle of summer, a high fever appears suddenly — 39–40°C (102–104°F). You look at the back of the throat and see a cluster of small blisters. There is no rash on the hands or feet. This is the classic presentation of herpangina. Like hand, foot, and mouth disease, it is caused by enteroviruses, and the two illnesses are frequently confused — the key difference is the distribution of lesions. Herpangina lesions are confined to the throat; HFMD also involves the hands, feet, and sometimes buttocks.
The greatest risk in herpangina is not the high fever itself. It is dehydration caused by the child being unwilling to swallow because of throat pain. Knowing this in advance makes the difference between a difficult week and a well-managed one.
The Virus and the Seasonal Pattern
Herpangina is caused primarily by Coxsackievirus A subtypes (A2, A4, A6, A10, and others), and also by EV-A71 in some cases [1]. Outbreaks peak in summer (June–August) and mainly affect children under 4 years of age. Annual case counts in Japan reach into the hundreds of thousands; herpangina and HFMD together define the characteristic summer infectious disease picture for young children [2].
The distinction from HFMD: in HFMD, lesions appear on the hands, feet, and inside the mouth. In herpangina, blisters appear only inside the mouth — specifically at the back, on the tonsillar pillars: the two arches of tissue flanking the tonsils at the back of the throat and soft palate: the rear muscular portion of the roof of the mouth, behind the bony hard palate (the structures at the entrance to the throat). "No rash on the hands or feet" is the key diagnostic feature.
Symptoms and Course
Onset is an abrupt high fever, typically 39–40°C (102–104°F). At roughly the same time, two to ten small blisters appear at the back of the throat. The blisters rupture quickly into shallow ulcers (aphthae: small, painful erosions on a mucous membrane, typically forming after blister rupture in the mouth or throat) and cause significant pain. This pain is the central management problem.
When throat pain prevents drinking, dehydration can develop within 24–48 hours. Younger children have smaller fluid reserves and reach the threshold faster.
Fever typically falls on its own in three to five days. The throat blisters and ulcers heal within about a week. Lasting complications do not occur in the typical case.
Managing the Dehydration Risk
Maintaining fluid intake is the top priority in herpangina care. When the child refuses normal liquids, these approaches often help:
- Cold drinks, ice cream, chilled gelatin desserts — cold and non-irritating
- Avoiding hot, spicy, or acidic foods and drinks, which worsen the pain
- Offering oral rehydration solution (ORS such as OS-1, chilled) in small, frequent amounts
When to seek medical care: no urination for six hours or more, lethargy or reduced responsiveness, or the child is essentially unable to drink at all. These are signs of potential dehydration.
Infection Control
Transmission routes are droplet and fecal-oral. Fecal viral shedding continues for two to four weeks after symptoms resolve [3]. Swimming pools are generally off-limits during the infectious period. Return to daycare or preschool depends on institutional policy; most facilities request the child stay home while fever is present and ulcers are active.
Putting It Into Practice
- "High fever + blisters at the back of the throat, no rash on hands or feet" — this combination points to herpangina
- Prioritize keeping fluid intake up, using cold foods as a tool — hydration is what the week is about
- Six hours without urination or marked lethargy → dehydration risk; see a doctor
- Log fever onset date, peak temperature, and how fluid intake changes from day to day — this makes it far easier to communicate the course if you contact the clinic
- Fecal shedding continues after recovery; sustain handwashing habits for a while after symptoms resolve
Summary
Herpangina resolves on its own in the great majority of cases within one week. The single most important thing to track is whether the child can drink. The throat pain is real and the reluctance to swallow is real — the work of the week is finding ways around it. Watching whether fluids are going in, not the height of the fever, is the core of home management.
References
- Ho M, Chen ER, Hsu KH, et al. An epidemic of enterovirus 71 infection in Taiwan. N Engl J Med. 1999;341(13):929–935. doi:10.1056/NEJM199909233411301. PMID: 10498487.
- National Institute of Infectious Diseases Japan. Herpangina: outbreak summary 2023. IASR. 2023;44(9). https://www.niid.go.jp/niid/ja/iasr.html
- Pallansch M, Roos R. Enteroviruses: polioviruses, coxsackieviruses, echoviruses, and newer enteroviruses. In: Knipe DM, Howley PM, et al., eds. Fields Virology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2013:490–530.
- Suzuki K, Yahata T, Hashimoto Y, et al. Epidemiological features of hand, foot and mouth disease and herpangina outbreaks in Saitama Prefecture, Japan. Jpn J Infect Dis. 2010;63(5):363–365. PMID: 20847466.