Wells syndrome (eosinophilic cellulitis) following vaccination: Two pediatric cases with positive patch test to aluminium salts

Abstract

K E Y W O R D S : aluminium salts, eosinophilic cellulitis, patch test, vaccine reaction, Wells cellulitis, Wells syndrome CASE REPORT Case 1. A 10-year-old boy with a past history of atopic dermatitis and allergic rhinitis presented with pruriginous erythematous annular plaques with vesicles on the dorsum of his right foot ( Figure 1A). The eruption appeared 12 days after he had received hepatitis B and human papillomavirus vaccines (Recombivax HB, Cervarix). Laboratory tests revealed eosinophilia of 1.000 × 10 9 /L (normal range < 0.600 × 10 9 /L). Cutaneous biopsy showed dermal and subcutaneous lympho-eosinophilic infiltrate with rare flame figures ( Figure 1B), suggesting the diagnosis of Wells syndrome. He was successfully treated with prednisone 0.5 mg/kg daily tapered over 6 weeks.Case 2. A 12-year-old girl with a past history of atopic dermatitis presented with pruriginous violaceous annular plaques on both legs (Figure 2A). The eruption appeared 14 days after she had received her second injection of human papillomavirus vaccine (Gardasil 9). Interestingly, 2 weeks after receiving her first injection, she had developed the same cutaneous eruption that persisted for 2 months, but she did not seek medical care at that time. No laboratory tests were done. A cutaneous biopsy showed an interstitial dermal infiltrate composed of lymphocytes, histiocytes, and eosinophils with numerous flame figures ( Figure 2B), also consistent with a diagnosis of Wells cellulitis. She also was successfully treated with prednisolone 0.5 mg/kg daily tapered over 2 weeks.

Eosinophilic cellulitis in response to BNT162b2 COVID‐19 vaccination

“…Common triggers include infection, arthropod bites, vaccinations, hematological and myeloproliferative disease and malignancy 1 . In children, the most commonly reported triggers are vaccinations 1,2 …”

“…The only identifiable trigger in this case was the BNT162b2 COVID‐19 mRNA vaccine, administered one day prior to onset of the rash. Seven other cases of vaccine‐triggered Wells syndrome have been reported with thimerosal, neomycin and aluminum hydroxide as the purported antigens 1,2 . Neither the mRNA‐1273 (Moderna) nor BNT162b2 (Pfizer‐BioNTech) COVID‐19 mRNA vaccines contain those ingredients 3 .…”

“…Our patient is up to date on his vaccinations and prior to receiving the BNT162b2 COVID‐19 mRNA vaccine had not experienced a similar rash. Wells syndrome is not life‐threatening and pre‐treatment with antihistamines can be considered prior to exposure to known antigens 2 …”

“…Seven other cases of vaccine‐triggered Wells syndrome have been reported with thimerosal, neomycin and aluminum hydroxide as the purported antigens. 1 , 2 Neither the mRNA‐1273 (Moderna) nor BNT162b2 (Pfizer‐BioNTech) COVID‐19 mRNA vaccines contain those ingredients. 3 Of the ingredients listed, polyethylene glycol is the only one with reported hypersensitivity reactions 3 , 4 suggesting that our patient may have experienced a hypersensitivity reaction to polyethylene glycol, a known antigenic trigger in the new mRNA vaccines.…”

“…Wells syndrome is not life‐threatening and pre‐treatment with antihistamines can be considered prior to exposure to known antigens. 2 …”