The appearance of morphea after vaccination has been reported to date as single and deep lesions that appear exactly at the site of the skin puncture. It was therefore postulated that the origin could be the trauma related to the injection. The aim of this article is to review the various hypotheses offered in the published literature about generalized morphea following vaccination. We present two cases of generalized morphea after COVID-19 vaccination and review the published literature on immune-related cutaneous reactions. As previously reported, antigenic cross-reactivity between vaccine spike proteins and human tissues could cause certain immune-mediated diseases, including generalized morphea. Herein we report two cases of generalized morphea probably induced by the COVID-19 vaccine, given the temporal relationship with its administration. In summary, environmental factors such as vaccination against SARS-COV-2 could induce an immune system dysregulation, which would have an important role in the pathogenesis of morphea. We present two cases of generalized morphea probably induced by the COVID-19 vaccine, given the time elapsed between vaccination and the onset of the skin lesions.

Colony-stimulating factor 1 receptor (CSF1R) inhibitors represent a new class of immune-modulatory drugs, mostly investigated in clinical trials in different malignant neoplasms. Four patients, diagnosed with recurrent or advanced malignant neoplasm and treated with a combination of anti-programmed death ligand 1 and anti-CSF1R monoclonal antibodies, developed an asymptomatic cutaneous eruption characterized by an ill-defined pseudoedematous to waxy diffuse infiltration with a reticular cobblestone-like pattern. Histopathological examination revealed diffuse mucin deposition involving the superficial and mid-dermis with fragmented and scattered elastic fibers. The exact pathogenic mechanisms implicated in the development of mucin deposits in patients treated with CSF1R inhibitors remain to be elucidated. A reduced degradation and clearance of components of the extracellular matrix by macrophages secondary to CSF1 pathway inhibition may be hypothesized. Shredding and fragmentation of elastic fibers may be a result of the increased accumulation of mucopolysaccharides. This observation illustrates the new spectrum of skin-related toxicities secondary to new targeting therapies. This may contribute to a better understanding of the underlying pathogenic mechanisms in skin diseases characterized by a persistent dermal glycosaminoglycan deposition.

Background: Organ transplant recipients (OTR) have a higher risk of actinic keratosis (AK) and keratinocyte carcinomas (KC). There are no clinical trials assessing the effectiveness of daylight photodynamic therapy (DPDT) to prevent new AK and KC in OTR. Objectives: To determine whether repeated treatments of field cancerization with DPDT are effective in preventing new AK and KC in OTR. Methods: A randomized, intra-subject controlled, evaluator-blind, split-face and/or scalp trial, from April 2016 to October 2018. Participants were OTR older than 18 years, 1-year posttransplant, with at least 5 AK on each hemi-face/hemi-scalp. One side received six field treatments with DPDT: two sessions 15 days apart at baseline, two at 3 months and two at 9 months after baseline. Control side received lesion-directed treatment with cryotherapy (double freeze-thaw) at baseline, 3 and 9 months. Total number of lesions (AK and KC) at 21 months, number of new AK and KC at 3, 9, 15 and 21 months and treatment preferences were analysed. Results: Of 24 men included, 23 were analysed at 3 months; and 21, at 9, 15 and 21 months. Mean (SD) age was 69.8 years (9.2). The total number of lesions at 21 months was 4.7 (4.3) for DPDT and 5.8 (5.0) for control side; P = 0.09. DPDT showed significantly lower means [SD] of new lesions compared to control side at 3 months (4.2 [3.4] vs. 6.8 [4.8]; P < 0.001), 9 months (3.0 [3.3] vs. 4.3 [3.4]; P = 0.04) and 15 months (3.0 [4.6] vs. 4.8 [5.0]; P = 0.02), and non-significant at 21 months (3.7 [3.5] vs. 5.0 [4.5]; P = 0.06). Most participants preferred DPDT. Conclusion: DPDT showed potential effectiveness in preventing new AK and KC in OTR by consecutive treatments of field cancerization. The preference for DPDT could facilitate adherence to the long-term treatment necessary in these patients.

Epidermal nevi are benign proliferations of the epidermis for which different treatments have been used with disappointing results due to their recurrences and anesthetic scars. Topical therapies have generally been ineffective and surgical treatment provides more definitive results, but with high risk of scarring. In recent years, multiple laser modalities have been described for the treatment of these lesions. In the literature, there are no reported cases of treatment of these lesions with Neodymium-doped Yttrium aluminum garnet (Nd:YAG) laser. We present the case of a 3-year-old patient with a hemicorporal epidermal nevus treated with Nd:YAG laser at an early stage with good results.