RESUMEN
Case report Erythema nodosum (EN) is considered a delayed type IV hypersensitivity reaction, triggered by exposure to an antigen, which diagnostic workout is usually challenging. Several conditions have been described as possible causes for EN, including infections, sarcoidosis, pregnancy, neoplasic and inflammatory diseases. Rarely, vaccines such as tetanus, diphtheria, BCG, hepatitis B, human papillomavirus, malaria, rabies, smallpox, typhoid, and cholera have been associated with subsequent EN. We present a 31-year- old leucodermic female with suppurative adenitis, who developed painful erythematous nodules on the pretibial area of the lower limbs. Ten days prior to presentation she had received the first dose of the COVID-19 mRNA-1273 vaccine. Fever, lymphadenopathy, fatigue, weight loss, arthritis, cough, diarrhoea, other organ-specifc symptoms and close contact with tuberculosis were excluded. She was under oral contraception for several years, that was not discontinued. Pregnancy was excluded. No positive signs were detected on physical examination besides the referred nodules. Laboratory tests revealed a normal complete blood count, erythrocyte sedimentation rate, C-reactive protein, antistreptolysin O titer, renal and hepatic tests. Interferon-gamma release assay was negative. Circulating rheumatoid factor was normal, anti-nuclear, anti-double stranded DNA and anti-neutrophil cytoplasmatic antibodies were negative. Angiotensin converting enzyme and protein electrophoresis were normal. Hepatitis B and C, HIV 1/2 and syphilis serologic profiles were negative. Urinalysis and fecal calprotectin were unremarkable. The patient was treated with naproxen and topic betamethasone dipropionate. Violaceous involution was reported, with complete resolution of the EN lesions over the following month. In the literature, there are rare reports of EN following SARS-COV2 infection and also after COVID-19 vaccination. To our knowledge this is the second report of EN after the COVID-19 mRNA-1273 vaccine. This case highlights the importance of clinical awareness for the possible association of COVID-19 vaccination and EN, adding to the already extensive list of causes included in the etiological investigation of these patients.
RESUMEN
Background: Following the use of COVID-19 vaccines worldwide, few cases of severe allergic reactions were reported. According to recent Portuguese guidelines, patients (pts) with suspected allergy to a COVID-19 vaccine component, history of anaphylaxis following vaccination, idiopathic anaphylaxis and mast cell disorders, should be referenced for Immunoallergology evaluation. Fear of a hypersensitivity reaction, especially among pts with allergic disease, is associated with lower vaccine adherence. This study aimed to evaluate BNT162b2 vaccination outcomes in pediatric pts with suspected severe allergic reactions prior to or after vaccination. Method(s): W e c onducted a p rospective s tudy i ncluding p ediatric pts with high risk of allergy to COVID-19 vaccine referred to Immunoallergology Department of a Tertiary Hospital. Demographic data, primary medical conditions and vaccination status were collected. After a detailed assessment by an allergologist, in selected cases, BNT162b2 vaccine administration in hospital facilities was performed, followed by a 1-hour observation period. Result(s): Twenty-two pts were included (18 males, 13.1+/-2.6years;min 7, max 17;13 atopic), referenced mainly from primary care (9) and other specialties (8). Most of the pts were referenced for the first dose of vaccine (18), due to mastocytosis/tryptasemia (5), previous allergic reaction to another vaccine (4), idiopathic anaphylaxis (3), complex comorbidities (2), drug anaphylaxis (1), parental reluctance (1), other (2). Four pts were evaluated for the second dose of COVID-19 vaccine, due to an acute urticaria after the first BNT162b2 vaccine dose. Three pts were eligible, after our evaluation, for primary care vaccination, that occurred without adverse reactions. Regarding the remaining 19 pts eligible for hospital vaccination, 13 were premedicated with oral antihistamines +/- montelukast. Eleven pts received BNT162b2 vaccine in hospital facilities [first dose (9);second dose (2)] with no reported adverse events. Vaccine administration was postponed in 3 pts due to SARS-CoV- 2 infection and 1 due to parental hesitancy. Conclusion(s): Our data support that allergic reactions to BNT162b2 vaccines are rare, even in the pediatric population with high risk of allergic reactions or with a history of previous severe allergic reactions. The favourable safety profile outcomes, along with the risk reduction of allergic reactions, increase vaccine confidence, broadening community protection.