Mucocutaneous lymph node syndrome, also known as Kawasaki disease, or acute febrile mucocutaneous lymph node syndrome, is a vasculitis syndrome characterized by fever, rash, conjunctival hyperemia, oral mucosal congestion, hard edema of hands and feet, and cervical lymphadenopathy, more common in young children.


Causes

The etiology is unknown. Genetic susceptibility and infection may be the cause of the disease. Various immune system abnormalities may occur in children with acute Kawasaki disease, suggesting that Kawasaki disease may be associated with viruses with high affinity for lymphoid tissues.


Signs and Symptoms

Kawasaki disease occurs mainly in children under 3 years of age, more in males than females, without obvious seasonality. The disease is self-limiting, persists for 6 - 8 weeks, and can last for several months to several years if with cardiovascular symptoms.

Fever is the first symptom, and the body temperature can be above 38 - 40°C. Continuous fever or remittent fever is present and can last for 1 - 2 weeks, and antibiotic treatment is ineffective.

Centripetal polymorphic erythema occurs during fever, resembling urticaria-like, measles-like, or scarlet fever-like rash, without blisters or crusting. Redness and decrustation occur in perianal skin.

In the early stage of fever, extensive hard edema of the hands and feet is present, finger and toe joints present with fusiform swelling, and diffuse erythema occurs in the palms and soles. In the recovery period, membranous decrustation occurs in the junctions of toes or fingers and skin, and the fingernails and toenails may fall off in severe patients.

Conjunctival hyperemia is present in the eyeballs, without purulent secretions or tears. Diffuse hyperemia is present in the oral pharyngeal mucosa, lips can be drying, chapping, bleeding, or crusting, and lingual papillae are raised and strawberry tongue is present.

Unilateral or bilateral cervical lymph node enlargement is present. Swollen lymph nodes are hard, 1.5cm or more in diameter, without fever, without suppuration, occurring during fever, regressing after reduction of fever. Sometimes auricular and occipital lymph nodes can be involved.

Cardiovascular symptoms and signs are less common, but a small number of children with coronary artery lesions present with apical systolic murmurs, distant heart sounds, arrhythmia, and heart enlargement in the early stage of fever. Congestive heart failure, pericarditis, and mitral regurgitation may occur at the end of fever, and hypertension or cardiogenic shock can also occur. Severe patients may suddenly die of coronary arteritis accompanied by aneurysm and thrombotic infarction.

Patients may develop pyuria, urethritis, diarrhea, vomiting, and abdominal pain, and few patients may present with hepatomegaly, mild jaundice, and increased serum transaminase activity. Lung infections are less common, and occasionally aseptic meningitis is present.


Histopathology

Dermal edema, vasodilatation, superficial and deep blood vessels surrounded by lymphocytes and histiocytes-based inflammatory cells infiltration, and some neutrophils and mast cells infiltration are visible. Systemic blood vessels can be involved, necrotizing arteries and aneurysms may be present in iliac arteries and coronary arteries, and phlebitis may be present in large veins.


Diagnosis

Diagnostic considerations include:

  • Unexplained fever for 5 days or longer
  • Conjunctival congestion
  • Oral mucosal changes such as flushing, clapping, crusting lips, diffuse flushing of the oral and pharyngeal mucosa, strawberry tongue
  • Limb changes such as hard, red, and swollen hands and feet, finger or toe tip desquamation, transverse furrows of the nails
  • Polymorphic eruption, without blisters or crusting
  • Enlargement of lymphnodes

Treatment

Symptomatic and supportive care is the main treatment regimen, including reduction of vascular inflammation and antiplatelet aggregation.

Aspirin is the first choice and has anti-inflammatory and anticoagulant effects. Treatment should continue until symptoms are relieved and erythrocyte sedimentation rate is normal, for about 1 - 3 months. Patients with coronary dilatation need to extend the treatment duration until the inner diameter of coronary artery is reduced to <3 mm.

High dose gamma globulin intravenous infusion in early stage can significantly reduce the incidence of coronary artery disease.

In addition to aspirin, dipyridamole can be used for antiplatelet aggregation. Patients with one or more giant coronary artery aneurysms, or multiple small to medium coronary artery aneurysms but without coronary occlusion, should take aspirin or warfarin for a long time. Coronary atherectomy can be applied in patients with coronary artery calcification.


Prognosis

About 10% - 20% of patients may die suddenly, more common in males less than 1 year old, mostly with fever for more than 16 days, leukopenia up to 30 × 109 / L (30,000 / mm3) or more, and ESR more than 101mm/h. The main cause of death is coronary embolism, and death occurs mostly within 1 month after onset.