Cross-groove spinning of the nail is an acute febrile pediatric disease with systemic vasculitis as the main lesion. The high incidence is in infants and children under 5 years of age, more in males than females, and less in adults and children under 3 months of age. Clinical manifestations may include fever, rash, enlarged non-purulent lymph nodes in the neck, congestion in the conjunctiva of the eyes, diffuse congestion in the oral mucosa, prune tongue, palmoplantar erythema, and hard edema of the hands and feet. Since this disease is highly susceptible to misdiagnosis or underdiagnosis, we understand the diagnostic criteria of the disease below. Unexplained fever >5 days, temperature above 39.0℃, ineffective antibiotic treatment, with 4 of the following 5 clinical manifestations, excluding other diseases: 1, bilateral bulbar conjunctival congestion, no purulent discharge. 2, diffuse congestion of oral and pharyngeal mucosa, red or chapped lips, prune tongue; 3, hard swelling of hands and feet and redness of palms and toes at the beginning of the disease, membranous peeling at the end of fingers and toes during the recovery period, perianal peeling; 4, polymorphic rash on the trunk, re-red rash and ulcers at the original scar; 5, enlarged lymph nodes in the neck, non-purulent. Note: If there are less than 4 out of 5 clinical manifestations, but the cardiac ultrasound indicates coronary artery damage, the diagnosis can also be confirmed.