Pediatric Dermatology Consult

A 19-month-old vaccinated female with 2 days of rash

A 19-month-old fully vaccinated female presented with 2 days of a progressive rash in the absence of fever. The rash started as a few small lesions on the left thigh that subsequently enlarged and spread to the face, trunk, buttock, and extremities. She appeared well and was eating, drinking, and ambulating with no report of joint pain or swelling. The lesions were not bothersome to her, and she was otherwise asymptomatic with no abdominal pain. On physical exam she had numerous oval red, bruiselike patches and edematous plaques predominantly on the buttocks and thighs with fewer lesions on the lower legs and upper arms. The hands and feet had a few smaller red papules with relative sparing of the palms and soles. There were numerous small red papules on the face with a background of patchy erythema and erythema of the bilateral ears. The trunk was relatively spared. She had no axillary or inguinal lymphadenopathy. Vital signs, complete blood count, comprehensive metabolic panel, C-reactive protein, lactate dehydrogenase, and fibrinogen were all within normal limits except for a minimally elevated blood urea nitrogen. Creatine was within normal range. Urinalysis was positive for leukocytes (3+), blood (2+), protein (1+), and nitrites (1+). The family denied preceding illness, travel, or new medications aside from one dose of cetirizine.

What is the diagnosis?

Kawasaki disease

IgA vasculitis (Henoch-Schönlein purpura)

Gianotti-Crosti syndrome (popular acrodermatitis of childhood)

Acute hemorrhagic edema of infancy

Erythema multiforme

Acute hemorrhagic edema of infancy (AHEI) is a leukocytoclastic vasculitis that typically affects children between 4 months and 2 years of age.1 Etiology is unknown but the majority of cases are preceded by infections, vaccinations, or certain medications.2

AHEI is a self-limited disease that runs a benign course with spontaneous resolution within days to 3 weeks.3 Classic presentation involves acute onset of fever, purpura, ecchymosis, and inflammatory edema. Edema is often the first sign, and may involve the face, ears, scrotum, or extremities. Hemorrhagic lesions may vary in size but often coalesce and present in a distinctive “cockade” or rosette pattern with scalloped borders. Systemic manifestations are rare, but renal and joint involvement may occur.4 Despite the dramatic and sometimes extensive appearance of the dermatologic manifestations, patients with AHEI are usually not in significant distress.

Courtesy Dr. David Schairer

Diagnosis is clinical, but skin biopsy may show leukocytoclastic vasculitis of the superficial small vessels with infiltrations of neutrophils, extravasation of red blood cells, and fibrinoid necrosis.5 In most cases, immunofluorescence is negative for perivascular IgA deposition. Treatment is symptomatic as the disease resolves spontaneously. Recurrence is uncommon but may occur, and usually occurs early.

Dr. Catalina Matiz, a pediatric dermatologist at Southern California Permanente Medical Group, San Diego

Dr. Catalina Matiz

What is on the differential?

Kawasaki disease. Similar to AHEI, patients with Kawasaki disease also may present with facial and extremity edema. However, patients with Kawasaki disease appear sicker, have associated lymphadenopathy, conjunctivitis, and fever longer than 5 days. The lack of elevated inflammatory markers, acute-onset, classic dermatologic lesions, and nontoxic appearance in our patient rule out Kawasaki disease and make AHEI more likely.

Elana Kleinman, a pediatric dermatology research associate in the division of pediatric and adolescent dermatology, University of California, San Diego, and Rady Children's Hospital, San Diego

Elana Kleinman

IgA vasculitis/Henoch-Schönlein purpura. The distinction between AHEI and Henoch-Schönlein purpura is among the most challenging. AHEI commonly afflicts younger children ranging from 4 months to 2 years, whereas Henoch-Schönlein purpura occurs in older children from 3 to 6 years of age. Visceral involvement is rare in AHEI, but frequently presents in Henoch-Schönlein purpura with gastrointestinal and renal complications. Although our patient had both mild renal involvement and a distribution primarily on the buttocks and lower limbs, similar to the classic distribution of Henoch-Schönlein purpura, the younger age and lack of gastrointestinal and arthritic manifestations make AHEI more likely.

Gianotti-Crosti syndrome. Gianotti-Crosti syndrome, also known as papulovesicular acrodermatitis of childhood, mainly affects children between the ages of 6 months and 12 years. Like AHEI, Gianotti-Crosti is a self-limiting condition likely triggered by viral infection or immunization. However, Gianotti-Crosti is characterized by a papular rash that may last for several weeks. Neither AHEI nor Gianotti-Crosti are pruritic, but patients with Gianotti-Crosti tend to have either inguinal or axillary lymphadenopathy. Our patient’s large, coalescing dusky red patches and edematous plaques without lymphadenopathy are more consistent with AHEI.

Courtesy Dr. David Schairer

Erythema multiforme. Erythema multiforme is an acute, immune-mediated condition characterized by distinctive target-like lesions on the skin often accompanied by erosions or bullae. Unlike AHEI, erythema multiforme can involve the oral, genital, and/or ocular mucosae. Erythema multiforme is rare before the age of 4 years. Although the targetoid or annular purpuric configuration of erythema multiforme may present similarly to AHEI in some cases, the young age of our patient and the lack of mucosal involvement make AHEI more likely.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego. Ms. Kleinman is a pediatric dermatology research associate at the University of California, San Diego, and Rady Children’s Hospital, San Diego. Neither Dr. Matiz nor Ms. Kleinman has any relevant financial disclosures.


1. Savino F et al. Pediatr Dermatol. 2013;30(6):e149-e152.

2. Carboni E et al. F1000Res. 2019;8:1771. 2019 Oct 17.

3. Fiore E et al. J Am Acad Dermatol. 2008;59(4):684-95.

4. Watanabe T and Sato Y. Pediatr Nephrol. 2007;22(11):1979-81.

5. Cunha DF et al. Autops Case Rep. 2015;5(3):37-41.

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