A 3-year-old boy is brought to the clinic by his parents for malaise, fever, and rash. The patient first developed malaise and fever 7 days ago, which has persisted despite administration of ibuprofen. Two days ago, the patient’s father noticed a rash on his trunk while bathing him. Since then, the rash has gradually spread to the patient’s arms and legs. The rash is neither painful nor itchy. Past medical history is unremarkable. Current medications include ibuprofen for fever and a daily multivitamin. Vital signs are temperature 30.2° C (102.7° F), blood pressure 94/59 mmHg, pulse 145 beats/min, and respirations 24/min. Height and weight are at the 60th percentile for age. Physical examination reveals a maculopapular rash over the chest, abdomen, back, and proximal upper and lower limbs. Ophthalmologic examination shows bilateral conjunctival injection without any exudate. On oral examination, the lips are cracked and the tongue is swollen and erythematous. There is edema and erythema of bilateral hands and feet, including the palms and soles. Lymph node examination reveals enlarged right-sided cervical lymph nodes.
Which of the following conditions is this patient at an increased risk for developing due to his current disease process?
B) Coronary artery aneurysm
This patient has findings consistent with a diagnosis of Kawasaki disease (KD). KD is a medium-vessel vasculitis classically seen in children < 5 years old, with the highest incidence in those who live in East Asia or who are of Asian descent. Diagnosis requires fever for ≥5 days along with at least four of the five principal clinic features: (1) painless bilateral conjunctival injection without exudate; (2) polymorphous (classically maculopapular) rash originating on the trunk; (3) cervical lymphadenopathy ≥ 1.5 cm (classically unilateral); (4) oropharyngeal mucositis (strawberry tongue - erythema and swelling of the tongue, cracked lips, or oropharyngeal erythema); and (v) erythema and edema of the hands and feet including the palms and soles.
Patients with KD are at an increased risk of coronary artery aneurysm, and subsequent thrombosis and rupture can be fatal. Patients should hence undergo screening echocardiography as soon as a diagnosis of KD is made. About 15-25% of patients with untreated KD will go on to develop coronary artery aneuryms. Treatment of KD is with aspirin and intravenous immunoglobulin (IVIG).
Answer choice A: Anterior ischemic optic neuropathy, is incorrect. Anterior ischemic optic neuropathy (AION) is a complication of giant cell (temporal) arteritis (GCA) and is a common cause of irreversible blindness in these patients. GCA is a large-vessel vasculitis classically seen in females > 50 years of age. The underlying pathophysiology involves focal granulomatous inflammation of the tunica media of the branches of the carotid artery, including the temporal artery. It usually presents with a unilateral headache, swelling or tenderness of the temporal artery, and jaw claudication. GCA is associated with polymyalgia rheumatica, an inflammatory proximal myopathy. Treatment is with high-dose steroids, which should be given prior to a diagnostic temporal artery biopsy to prevent blindness.
Answer choice C: Gangrene and autoamputation of digits, is incorrect. This is seen in Buerger disease (thromboangiitis obliterans), a medium-vessel vasculitis usually seen in males < 40 years old and strongly associated with a history of tobacco smoking. Buerger disease is characterized by segmental, nonatherosclerotic vaso-occlusive thrombosis of the vessels of the extremities. The inflammation may extend to the adjacent vein and nerve. Patients present with migratory superficial thrombophlebitis (tender nodules along the affected vein), Raynaud phenomenon (recurrent vasospasm of the fingers and toes in response to cold or stress), and intermittent claudication that typically begins in the hands and feet and progresses proximally. Physical examination often reveals absent distal pulses. In late-stage disease, critical ischemia can cause gangrene and autoamputation of digits. Treatment involves smoking cessation.
Answer choice D: Granulomatous thickening and narrowing of the aortic arch, is incorrect. This is a complication of Takayasu arteritis, a large-vessel vasculitis classically seen in females < 40 years old and of Asian descent. It usually presents with skin nodules, ocular disturbances, movement-induced myalgia, arthralgia, night sweats, and fever. Weak upper extremity pulses are a classic finding. Treatment is with high-dose steroids along with a steroid-sparing agent such as methotrexate or azathioprine.
Answer choice E: Transmural inflammation and microaneurysms of renal blood vessels, is incorrect. This finding is seen in patients with polyarteritis nodosa (PAN), a medium-vessel vasculitis usually seen in middle-aged males. It is a type III hypersensitivity reaction and is commonly associated with hepatitis B virus (HBV) infection. PAN usually affects vessels of the skin, kidney, gastrointestinal tract and peripheral nerves; the lungs are characteristically spared. It usually presents with constitutional symptoms (e.g., fever, weight loss, headache, malaise) and further manifestations vary based on organ involvement. The diagnosis is confirmed by biopsy (different stages of transmural inflammation with fibrinoid necrosis) or angiography (innumerable renal microaneurysms and spasms). Treatment includes steroids and cyclophosphamide. Antiviral therapy is effective for hepatitis B virus-associated PAN.
Key Learning Point
Kawasaki disease is a vasculitis usually seen in children < 5 years old and is more common in those of Asian descent. Clinical features include fever, conjunctival injection, polymorphous rash, cervical adenopathy, oropharyngeal mucositis, and hand and foot edema and erythema. All patients with Kawasaki disease should undergo echocardiographic screening for coronary artery aneurysm, a potentially fatal complication.
