This is a multicenter clinical trial investigating the safety and efficacy of inhaled Peginterferon α-2b at different doses, in combination with supportive care, for the treatment of patients with hand, foot, and mouth disease (HFMD) of ordinary type. The trial aims to enroll 90 patients with HFMD. Eligible subjects will be randomly assigned to receive either supportive care + Peginterferon α-2b mcg or supportive care + Peginterferon α-2b 90 mcg, administered on days 1 and 3. The study period includes a 3-day screening phase and a 5-7 day inpatient visit period. The results of this trial will be used to evaluate safety and efficacy.

Inclusion Criteria:

-1. Age: 1 year of age ≤ Age ≤ 6 years of age. 2.Gender: Both male and female. 3.Clinical symptoms/signs: Manifesting as common type HFMD (Stage 1, rash stage), with fever or rash symptoms first occurring within 72 hours prior to the signing of the informed consent form.

4.Informed consent: Guardians understand and sign the informed consent form (if the guardian is the parent, both parents must sign).

Exclusion Criteria:

• (1) Severe or Critical HFMD Presentation at Enrollment

  1. Manifesting as severe HFMD (Stage 2, neurological involvement phase)

  2. Manifesting as critical HFMD (Stage 3 or 4, cardiopulmonary failure phase) with any of:

     Brainstem encephalitis, encephalomyelitis, or meningitis,Neurogenic pulmonary edema or respiratory failure requiring mechanical ventilation,Shock or circulatory collapse.

  3. Concurrent multi-organ failure requiring ICU monitoring

     (2) Allergy History and Treatment History

  1. Received interferon, ribavirin, acyclovir, ganciclovir, or vidarabine monophosphate within 30 days prior to screening or current use

  2. Received immunoglobulin or glucocorticoid therapy within 30 days prior to screening or current use

  3. Known hypersensitivity to interferon or its components, or other clinically significant allergies contraindicating participation

  4. Use of other investigational drugs within 3 months or 5 half-lives (whichever is longer) prior to screening, or current participation in medical device trials

     (3) Medical History

  1. Congenital heart disease, severe malnutrition, immune dysfunction, asthma, or other severe systemic diseases

  2. Active HBV, HCV, HIV, or Treponema pallidum infection

  3. History of malignant tumors (current or prior)

  4. History of epilepsy, neurological/psychiatric disorders, or relevant family history

     (4) Clinical Parameters: Resting respiratory rate >40 breaths/min,Heart rate >160 bpm

     (5) Other Considerations: Any condition deemed by investigators to render participation medically inadvisable