Make the Diagnosis

A toddler with a fever and desquamating perineal rash

Publish date: May 14, 2020

An otherwise healthy 18-month-old female presented to the emergency department with 5 days of fever, erythema, fissuring of the lips, conjunctival injection, and a desquamating perineal rash. In addition, she had nasal congestion and cough for which she was started on amoxicillin 2 days prior to presentation given concern for pneumonia.

On exam, she was also noted to have several palpable cervical lymph nodes and edematous hands with overlying erythema. Laboratory evaluation was notable for respiratory syncytial virus positivity by polymerase chain reaction assay, leukocytosis, and elevated inflammatory markers (erythrocyte sedimentation rate and C-reactive protein).

Kawasaki disease

Given the presentation of persistent fever, nonpurulent conjunctivitis, cracked lips, erythematous tongue, desquamating perianal rash, and acral edema and erythema, suspicion was high for Kawasaki disease (KD). An echocardiogram revealed diffuse dilation of the left anterior descending artery without evidence of an aneurysm. The patient was promptly started on 2 g/kg IVIG and high-dose aspirin. She was later transitioned to low-dose aspirin. Long-term follow-up thus far has revealed no cardiac sequelae.

KD, or mucocutaneous lymph node syndrome, is a multisystem vasculitis with predilection for the coronary arteries that most commonly affects children between 6 months and 5 years of age.¹ While the etiology remains unclear, the pathogenesis is thought to be the result of an immune response to an infection in the setting of genetic susceptibility.¹ Approximately 90% of patients have mucocutaneous manifestations, highlighting the important role dermatologists play in the diagnosis and early intervention to prevent cardiovascular morbidity.

The diagnostic criteria include fever for at least 5 days accompanied by at least four of the following:

Bilateral bulbar conjunctival injection without exudate that is classically limbal sparing.
Oral mucosal changes with cracked fissured lips, “strawberry tongue,” or erythema of the lips and mucosa.
Changes in the extremities: erythema, swelling, or periungual peeling.
Polymorphous exanthem.
Cervical lymphadenopathy, often unilateral (greater than 1.5 cm).

^{Courtesy Dr. Elizabeth H. Cusick and Dr. Molly E. Plovanich, department of dermatology at the University of Rochester (N.Y.)}

Although nonspecific for diagnosis, laboratory abnormalities are common, including anemia, thrombocytosis, leukocytosis, elevated inflammatory markers, elevated alanine aminotransferase (ALT), hypoalbuminemia, and sterile pyuria on urine analysis.¹

Notably, a classic finding of KD is perineal dermatitis with desquamation occurring in the acute phase of disease in 80%-90% of patients.^2-5 In a retrospective review, up to 67% of patients with KD developed a perineal rash in the first week, most often beginning in the diaper area.² The perineal rash classically desquamates early during the acute phase of the disease.¹

While most individuals with KD follow a benign disease course, it is the most common cause of acquired heart disease in the United States.¹ Treatment is aimed at decreasing the risk of developing coronary abnormalities through the prompt administration of IVIG and high-dose aspirin initiated early in the acute phase.⁶ A second dose of IVIG may be given to patients who remain febrile within 24-48 hours after treatment.⁶ Infliximab has been used safely and effectively in patients with refractory KD.⁷ Long-term cardiac follow-up of KD patients is recommended.

Recently, there has been an emerging association between COVID-19 and pediatric multi-system inflammatory syndrome, which shares features with KD. Patients with pediatric multi-system inflammatory syndrome who meet clinical criteria for KD should be promptly treated with IVIG and aspirin to avoid long-term cardiac sequelae.

This case and the photos were submitted by Dr. Elizabeth H. Cusick and Dr. Molly E. Plovanich, both with the department of dermatology at the University of Rochester (N.Y.). Dr. Donna Bilu Martin edited the case.

Dr. Donna Bilu Martin

Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to dermnews@mdedge.com.