key: cord-0972368-vn3dvhlh
authors: Dawoud, Noha Mohammed; Aslam, Huma; Ali, Ishraga Mahmoud; Dawoud, Marwa Mohammed
title: The first case report of Pityriasis lichenoides chronica following COVID‐19 mRNA vaccination
date: 2022-03-21
journal: Dermatol Ther
DOI: 10.1111/dth.15445
sha: 5db776bfdc62c4dd4c0b194ea33715b75fba4ab6
doc_id: 972368
cord_uid: vn3dvhlh

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ties, with the appearance of numerous purpuric lesions. Mucous membranes and nails were free. A skin biopsy was taken after signing a written consent. It revealed parakeratosis, moderate spongiosis and focal vacuolar alteration of the basal cell layer. The papillary dermis showed mild edema, and extravasated red cells, with superficial and deep dermal perivascular, predominantly lymphocytic infiltrate, and was diagnosed as PLC ( Figure 1C ,D). Laboratory investigations including complete blood count, liver function, renal panel, C-reactive protein and erythrocyte sedimentation rate, were normal. Serology for HCV, HBV, HIV and ANCA antibodies were negative. SARS-Cov-2-IgG was positive (index > 40,000 AU/ml)).

Although the patient was prescribed doxycycline 100 mg cap twice per day with narrow band ultraviolet B (nb-UVB) phototherapy twice per week and topical clobetasone dipropionate cream and Tacrolimus 0.1% ointment, new crops of lesions continued to appear over 6 weeks of follow-up. The prescribed antibiotic was then changed to azithromycin 500 mg on day one followed by 250 mg once daily for 3 days, and the course was repeated every other week for 8 weeks with continued nb-UVB sessions. Lesions started to subside with no new lesions over the next 2 months.

One month following skin clearance, the patient acquired COVID-19 infection confirmed by nasopharyngeal swab COVID-19 PCR. However, he did not develop flare up of his subsided lesions.

Immunogenic response to vaccines alters cytokines levels activating different key players of the innate and adaptive immune system.

The skin and mucosa are greatly influenced by the non-specific activation of the immune system sparked by vaccines. 1 Pityriasis lichenoides (PL) are spectrum of rare cutaneous inflammatory diseases which affect mainly children and young adults. It is known to be triggered by extrinsic antigens such as infectious agents, drugs and vaccines. 2 Only 10 reports of vaccine-induced cases were previously documented following different types of vaccines such as measles, rubella, mumps, influenza, adult tetanus, diphtheria, and human papilloma virus vaccines. 3 Up to date, pityriasis lichenoides et varioliformis acuta (PLEVA) and PLEVA-like eruption has been reported three times following BioNTech/Pfizer COVID-19 vaccination (Table 1) . [4] [5] [6] It was also reported in 10 pediatric patients following COVID-19 infection. 7 Moreover, a 42-year-old female was documented to develop PLC suddenly following COVID-19 infection. 8 Thus, our presented adolescent boy is the first PLC case to be reported (also in pediatrics) following COVID-19 mRNA vaccine.

In vaccine triggered cases, three pathogenic hypotheses are However, this suspicion warrants further research and investigations.

Using Naranjo adverse drug reaction probability scale, the reaction was considered possible (score 4). 11 Thus, it has to be stressed 

Cutaneous adverse reactions to COVID-19 vaccines: insights from an immuno-dermatological perspective. Vaccines (Basel)

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Pityriasis lichenoides et varioliformis acuta triggered by human papillomavirus vaccine: a case report and literature review

Abrupt onset of sweet syndrome, pityriasis rubra pilaris, pityriasis lichenoides et varioliformis acuta and erythema multiforme: unravelling a possible common trigger, the COVID-19 vaccine

Lymphomatoid drug reaction developed after BNT162b2 (comirnaty) COVID-19 vaccine manifesting as pityriasis lichenoides et varioliformis acuta-like eruption

Pityriasis lichenoides et varioliformis acuta following COVID-19 mRNA vaccination

Papulo-purpuric dermatitis of childhood: a distinct PLEVA-like eruption associated to SARS-CoV-2 infection. Clinical, histopathological and immunohistochemical study of 10 cases

A case of pityriasis lichenoides chronica in a patient with COVID-19 infection

Varicella-zoster and herpes simplex virus reactivation post-COVID-19 vaccination: a review of 40 cases in an international dermatology registry

Pityriasis lichenoides chronica associated with herpes simplex virus type 2

A method for estimating the probability of adverse drug reactions