Tangled Truths: Unraveling the Link Between Frontal Fibrosing Alopecia and Allergic Contact Dermatitis.

Frontal fibrosing alopecia (FFA) is an increasingly common diagnosis, especially in middle-aged women, and has garnered growing attention in the scientific literature. This variant of lichen planopilaris (LPP) is recognized as a progressive scarring alopecia affecting the frontal and temporal regions of the scalp as well as the eyebrows and occasionally other sites. Although its precise etiology remains elusive, various factors such as genetics, medications, hormonal influences, and environmental exposures-including specific chemicals present in sunscreens-have been implicated in its pathogenesis but without evidence of causality. The potential relationship between contact allergy and FFA has been explored, with some suggesting an increased prevalence of contact allergy among patients diagnosed with FFA. This article aims to explore the potential association between contact allergy and FFA, focusing on the current published literature and implicated allergens.

Post-radiation lichen planus: a case report and review of the literature.

BACKGROUND: Lichen planus is a T-cell mediated inflammatory disorder of the skin and mucus membranes and is a rare complication of external beam radiation. CASE PRESENTATION: 64 year old White male who presented to dermatology with a lesion at the lateral aspect of the right thigh. The lesion was first noted 40 years prior and had grown from 1.5 cm to 6.5 cm in the ensuing years. On examination the lesion was raised, hypopigmented, with pearly borders and central ulceration. Wide excision with lymph node dissection demonstrated invasive squamous cell carcinoma, basaloid type, with negative margins. Patient had radiation therapy of the right inguinal nodes. Patient subsequently noted a "blister" on the right upper thigh, which progressed over time to flat, polygonal, intensely pruritic lesions that covered the right lateral thigh from just distal to the hip to the distal third of the femur (Figs. 1, 2). Skin biopsy was positive for lichen planus. He was started on topical triamcinolone with salutary effects on appearance and pruritus. Fig. 1 Lichen planus, right thigh Fig. 2 Closeup, lichen planus, right thigh, demonstrating polygonal papules CONCLUSION: Once more biopsy-proven cases of post-radiation lichen planus are reported, hopefully the exact mechanism can be elucidated. This may identify risk factors and aid in treatment, with the goal of limiting radiation toxicity and palliation of symptoms that may affect the quality of daily life.

[Lichen planus]. / Lichen planus.

Lichen planus is an inflammatory disorder of the skin and/or mucosa. Immune dysregulation, infections, environmental and genetic factors play a role in its pathogenesis. Clinically, there are 6 important distinctive manifestations. The mucosal subtypes manifest inside the mouth, oesophagus, genitalia and - although less often - the nose, ear canal, tear duct and conjuctiva. The non-mucosal subtypes occur on the skin, scalp (hair follicles) and nails. Patients may suffer from several subtypes of lichen planus. Unfamiliarity with the different manifestations may lead to a delay in diagnosis and thus to insecurity and distress in patients. The advice to all healthcare providers is to ask patients with lichen planus about symptoms of all subtypes and clinically inspect the skin and mucosa, or to refer the patient to a dermatologist.

Lichen planus after COVID-19 infection and vaccination.

Lichen planus (LP) is an inflammatory disorder believed to result from CD8 + cytotoxic T-cell (CTL)-mediated autoimmune reactions against basal keratinocytes. We present a review of LP following COVID-19 infection and vaccination. Literature searches were conducted on PubMed and Google Scholar from 2019 to 7/2022. 36 articles were selected based on subject relevance, and references within articles were also screened. 39 cases of post-vaccination LP and 6 cases of post-infection LP were found among case reports and case series. 152 cases of post-vaccination LP and 12 cases of post-infection LP were found in retrospective and prospective studies. LP is a rare complication of COVID-19 infection and vaccination that may be mediated by overstimulation of T-cell responses and proinflammatory cytokine production. However, it does not represent a limitation against COVID-19 vaccination, and the benefits of vaccination considerably outweigh the risks.

Association of childhood vaccination with pediatric lichen planus: A systematic review.

Lichen planus (LP) is a chronic T-cell-mediated mucocutaneous inflammatory disease, largely recognized in adults. It is uncommon in children, and the literature present still lacks comprehensive understanding mainly due to underreporting of such cases. LP shows atypical clinical features, when seen in children, mainly affecting the flexor aspect of the wrists, legs, and the oral and genital mucosae. It is largely considered an autoimmune response of the body with various etiologic factors. Its association with vaccination is still an interesting field for research. The focus of the present systematic review was to discover the link of vaccine in the pathogenesis of juvenile LP. An electronic search was carried out using MEDLINE by PubMed, Google Scholar, and Web of Science databases. Articles that reported LP in children with prior records for vaccination were selected for the present systematic review. Twenty-three published articles in the English language were included for the quantitative and qualitative syntheses. The demographic data, specific vaccine history, and clinical details of the lesions were recorded. The existing evidence supports that vaccines could play an important role in etiopathogenesis of pediatric LP.

Lichen planus and lichen planopilaris flare after COVID-19 vaccination.

We report two cases of lichen planus following COVID-19 vaccination in two middle-aged women, where the first patient presented with lichenplanopilaris (LPP) relapse and development of lichen planus 14 days after the second dose of AstraZeneca vaccine, and the other patient who had a previous scattered lesion of LP which extended and increased in severity after the first and second dose of Sinopharm. The suggested cause could be due to immune dysregulation and up regulation of T cell lymphocytes which was triggered after COVID-19 vaccination. What supports our hypothesis that LP had occurred due to COVID-19 vaccination, is that one of the patients responded successfully to Metronidazole. This means that the infection process after vaccination could be the cause in aggravating LP. To add, one of the suggested mechanisms for the appearance of LP or reactivation of a dormant LPP can be cytotoxic CD8 T-lymphocytes which increase the secretion of IFN-γ and IL-5 cytokines and may also result in basal keratinocytes' apoptosis leading to cutaneous manifestations. This was supported by the efficacy of Tofacitinib that was used in the other patient who presented with reactivation of LPP in addition to LP. Tofacitinib decrease the number of T cell infiltration and adjust IFN expression.