Numerous morphologies of skin rashes have been described in the setting of COVID-19, including pernio, livedoid rash, exanthem, and vasculitis. This classic constellation of symptoms (palpable purpura on buttocks/legs, abdominal pain, arthralgia, hematuria) is highly consistent with Henoch-Schonlein purpura (HSP). There are now multiple case reports of COVID-19–associated HSP.
HSP is the most common type of childhood systemic vasculitis. It is mediated by immunoglobulin A (IgA) immune complex deposition and has been associated with respiratory tract infections, streptococcal species, parainfluenza virus, and human parvovirus B19, medications, vaccinations, and malignancies. HSP is usually a self-limiting disease, with a course over 4-6 weeks, and can affect multiple organs, including the skin, gastrointestinal tract, joints, and the kidneys. The diagnostic criteria include palpable purpura in the presence of one or more of the following: diffuse abdominal pain, arthritis or arthralgia, any biopsy showing predominant IgA deposition, and renal involvement in the form of hematuria or proteinuria. Renal disease is variable and is the most significant indicator of long-term prognosis. This teenager was treated with oral corticosteroids because of the severe periarticular edema and responded rapidly. His subsequent urine analyses normalized.
What is on the differential?
Multisystem inflammatory syndrome in children (MIS-C) is a rare, potentially fatal, complication of COVID-19 infection that causes inflammation of multiple organs, including the heart, lungs, kidneys, brain, skin, eyes, or the gastrointestinal tract. It commonly affects children around ages 8-9 years. Initial symptoms include fever, rash, red eyes, diarrhea, and vomiting that appear 2-6 weeks post COVID-19 infection. Like HSP, MIS-C can present with edema of the extremities, worsening hand/foot pain, and hematuria; however, the absence of both fever and the pattern of system involvement seen with MIS-C and classic findings in this patient are more consistent with HSP.
Reactive infectious mucocutaneous eruption (RIME) was recently coined to encompass both infection-associated Stevens-Johnson eruptions including Mycoplasma pneumoniae-induced rash and mucositis (MIRM) and mucocutaneous eruptions caused by nonmycoplasma pathogens (including Chlamydia pneumoniae, human parainfluenza virus 2, rhinovirus, adenovirus, enterovirus, human metapneumovirus, influenza B virus, and COVID-19). It is usually seen in male children and adolescents. Prodromal symptoms include cough, fever, and malaise and they precede the prominent feature of mucositis. Our patient’s lack of mucosal involvement is not consistent with RIME.
Perniosis (chilblains) is characterized by localized edematous patches of erythema or cyanosis on exposed extremities, that may be associated with cold exposure. Lesions are usually symmetric and self-limiting, and symptoms can include numbness, tingling, pruritus, burning, or pain. Pernio-like skin lesions have been seen during the COVID-19 pandemic, though many patients have negative testing for infection by PCR and serology. Pernio may also be seen with autoimmune diseases or malignancy.
Meningococcemia is a rare disease caused by infection with gram-negative diplococci bacteria Neisseria meningitidis and spreads through saliva or respiratory secretions. Its clinical presentation can vary widely, from transient fever to fulminant disease. It is characterized by upper respiratory tract infection, fever, and petechial lesions associated with thrombocytopenia and coagulopathy.
Dr. Eichenfield is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego, and Rady Children’s Hospital, San Diego. Ms. Laborada is a pediatric dermatology research associate in the division of pediatric and adolescent dermatology at the University of California, San Diego, and Rady Children’s Hospital. Dr. Eichenfield and Ms. Laborada have no relevant financial disclosures.
References
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