Utility of IL-36 immunostaining in distinguishing psoriasis from pityriasis rosea and pityriasis lichenoides.

BACKGROUND: Psoriasis is an inflammatory skin disease driven by upregulation of cytokines in the Th17 pathway, including interleukin-36 (IL-36). Previous studies have highlighted the utility of IL-36 immunostaining for psoriasis compared to spongiotic dermatitis and other psoriasiform dermatoses; however, no study has examined the role of IL-36 staining in distinguishing psoriasis from pityriasis rosea (PR) and pityriasis lichenoides (PL), known histologic mimickers of psoriasis. METHODS: We compared the immunostaining pattern of IL-36 for 21 PR cases, 22 PL cases, and 10 psoriasis cases. We graded the immunostaining as 0, negative; 1, focal weak; 2, diffuse weak; 3, focal, strong; or 4, diffuse strong. We further categorized stains as negative (0-2 score) or positive (3-4 score) and utilized Fisher's exact test to compare the immunostaining pattern of these entities. RESULTS: All psoriasis specimens were positive for IL-36, whereas all PR specimens were negative (p = 0.00000002). Twenty PL specimens were negative (p = 0.000001). Nine of 10 pityriasis lichenoides et varioliformis acuta cases were negative (p = 0.00012), and 11 of 12 cases of pityriasis lichenoides chronica were negative (p = 0.00003). CONCLUSIONS: Our findings highlight the potential role of IL-36 immunostaining in distinguishing psoriasis from other psoriasiform dermatoses, including PR and PL.

Efficacy and safety of excimer light (308 nm) in the treatment of pityriasis lichenoides chronica.

INTRODUCTION: Pityriasis lichenoides chronica is the chronic end of the spectrum of pityriasis lichenoides which have several forms of papulosuamous conditions. Several treatments obtained complete clearance of the condition including phototherapy and specifically narrow band ultraviolet B. The Excimer light 308 is a monochromatic light that acts within the ultraviolet B wavelength and used as a targeted phototherapy in several skin conditions. METHODS: Thirty-four patients with histopathologically diagnosed pityriasis lichenoides chronica underwent treatment with biweekly sessions of excimer light 308 nm. Treatment continued until complete clearance was obtained or to a maximum of 48 sessions (24 weeks). RESULTS: Thirty-one patients obtained complete clearance with no recurrence till the end of the study period, two patients had partial response and only one patient showed poor response to treatment. CONCLUSION: Excimer light can be a safe and effective treatment of pityriasis lichinoides chronica in different ages and genders.

Pityriasis lichenoides: assessment of 41 pediatric patients.

OBJECTIVES: This study aims to evaluate the characteristics and treatment response of patients with pityriasis lichenoides seen in the last 43 years in a pediatric dermatology service. METHODS: This was a retrospective, analytical, longitudinal study of patients under 15 years of age. The medical records were reviewed and data were presented as frequencies, means and variances. Student's t-test, Mann-Whitney test, Fisher's exact test, Pearson/Yates chi-square test and multivariate logistic regression model were used, with p < 0.05 considered. RESULTS: 41 patients were included, 32 (78.0%) with pityriasis lichenoides chronica (PLC), five (12.2%) with pityriasis lichenoides et varioliformis acuta (PLEVA) and four (9.8%) with clinical PLC without biopsy. The age range of school children and adolescents was 19 (46.3%) and 13 (31.7%) respectively and 27 (65.8%) were male. Two peaks of the highest frequency were observed between 2004 and 2006 (10 patients - 24.4%) and another between 2019 and 2021 (6 patients - 14.7%). There was remission in 71.9% (n = 23), with 56.6% (n = 17) of those who used antibiotic therapy and 80% (n = 4) of those who had phototherapy. The chance of remission was 13 times greater in patients with disease onset after 5 years of age. CONCLUSIONS: The clinical form most commonly found was PLC mainly in school children and adolescents. The frequency peaks coincided with infectious outbreaks. The remission rate was satisfactory with antibiotic therapy, but higher with phototherapy. Remission was greater in patients with disease onset after 5 years of age.

Rapid recovery in a child with febrile ulceronecrotic Mucha-Habermann disease following intravenous immunoglobulin administration.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD), a lymphocyte-mediated inflammatory skin disorder, is considered a severe variant of pityriasis lichenoides et varioliformis acuta that can lead to a fatal outcome if not managed in a timely fashion. Children with FUMHD can have systemic complications involving various organs. The scarcity of reported cases and the absence of well-designed studies or randomized clinical trials to evaluate different therapeutic modalities pose a major challenge in treating this potentially life-threatening disorder. We report a five-year-old child with FUMHD and seizures treated unsuccessfully with a combination of systemic steroids, methotrexate, dapsone, and oral erythromycin, who improved rapidly and achieved disease control with just a single infusion of low-dose intravenous immunoglobulin.

Pityriasis lichenoides presented with skin rash mimicking Urticaria: A case report.

BACKGROUND: Acute urticaria is urticaria with or without angioedema that is present for less than six weeks, while chronic urticaria is present for more than six weeks. Pityriasis lichenoides (PL) is a benign cutaneous inflammatory disease of unknown etiology. Acute PL typically resolves within a few weeks, while chronic PL lasts several months. The skin rash of PL may resemble the rash of other conditions, so the distinction is essential and depends on history and physical examination and is confirmed by skin biopsy. CASE REPORT: A 64-year-old gentleman presented with seven days history of generalized itchy skin (hives). Individual lesions last 24-48 hours and do not leave pigmentation or scarring. No systemic involvement. No specific triggers, with two previous similar episodes 30 years and 20 years ago. Levocetirizine, 5 mg tablet, was prescribed, and he was instructed to increase the dose to 4 tablets daily if needed. On reassessing the patient after ten days, he did not respond well. The rash was different from the initial one, with individual lesions lasting for five days or more, so he was referred to a dermatologist for a skin biopsy. Basic investigations were normal. Performing skin biopsy is needed to exclude other pathologies. Skin biopsy showed pathological changes of lichenoid dermatitis compatible with pityriasis lichenoides et varioliformis acuta (PLEVA). He has been treated with azithromycin 250 mg daily for three weeks with rapid and complete resolution without scaring. CONCLUSION: Urticarial rash may mimic the skin rash of other conditions. Detailed serial history and physical examination are warranted to exclude other diagnoses. Skin biopsy is needed when diagnosing conditions other than urticaria are suspected.

Narrowband ultraviolet B phototherapy for pityriasis lichenoides: A real-life experience.

INTRODUCTION: Pityriasis lichenoides (PL) is a papulosquamous disease affecting both children and adults, for which narrowband-UVB (NB-UVB) phototherapy is regarded as a commonly used treatment option. The aim of this study was to investigate the efficacy of NB-UVB phototherapy in the management of PL and to compare response rates in pediatric and adult age groups. MATERIALS AND METHODS: This observational, retrospective study included 20 PL patients (12 pityriasis lichenoides chronica; PLC, 8 pityriasis lichenoides et varioliformis acuta; PLEVA) who failed to respond to other treatment modalities. The data for this study were collected retrospectively from patient follow-up forms in the phototherapy unit. RESULTS: A complete response (CR) was obtained in all pediatric patients with PL, while 53.8% of adult patients had achieved CR. The mean cumulative dose required to achieve the CR was higher in pediatric patients than adult patients with PL (p < .05). The CR was achieved in 6 (75%) of 8 PLEVA patients, while 8 (66.7%) of 12 PLC patients had reached to CR. The mean number of exposures for patients with PLC to achieve a CR was higher than patients with PLEVA (p < .05). Erythema was the most common adverse effect during phototherapy particularly in 5 (35.7%) of the patients with PL who had achieved CR. CONCLUSIONS: NB-UVB is an effective and well-tolerated treatment option for PL especially in diffuse types. A higher response can be obtained in children with higher cumulative dose. Patients with PLC may require more exposures for CR than patients with PLEVA.

Febrile ulceronecrotic Mucha-Habermann disease during pregnancy: A case report.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a rare and severe form of 'pityriasis lichenoides et varioliformis acuta', with a progressive and potentially fatal course. To the best of our knowledge, there has been no reported case of FUMDH during pregnancy before. Due to life-threatening nature of the disease and the lack of evidence-based treatment, management of FUMHD in pregnancy is a therapeutic challenge. Additionally, some of the drugs that are effective in the treatment are contraindicated in pregnancy. Herein, we report a 27-year-old woman diagnosed with FUMHD in her 19th week of pregnancy and treated with ceftriaxone and erythromycin.

Pityriasis Lichenoides-Like Mycosis Fungoides: A Case Report.

A rare subtype of mycosis fungoides (MF) known as pityriasis lichenoides-like mycosis fungoides (PL-like MF) manifests as recurrent crops of erythematous scaly papules with the histological findings of MF. We report a 64-year-old male with recurrent crops of psoriasiform papules with mild scales on his trunk and extremities. Skin biopsy results were consistent with CD8+ cutaneous T-cell lymphoma (CTCL). Our patient had clinical features of pityriasis lichenoides and histological findings consistent with CD8+ MF. A differential diagnosis of PL, lymphomatoid papulosis (LyP), and PL-like MF was considered. Counseling patients with CD8+ cutaneous T-cell lymphoma can be challenging, as there is an aggressive variant named primary cutaneous aggressive epidermotropic CD8+ CTCL. However, with the ability to recognize PL-like MF, a rare indolent type of CD8+ CTCL, physicians can counsel patients appropriately.

Post-Inflammatory Hypopigmentation: Review of the Etiology, Clinical Manifestations, and Treatment Options.

Post-inflammatory hypopigmentation is a common acquired pigmentary disorder that is more prominent in skin of color, leading to great cosmetic and psychosocial implications. Often, a diagnosis with a pigmentary disorder can negatively impact an individual's health-related quality of life and may result in stigma. Although most cases of post-inflammatory hypopigmentation resolve spontaneously over time, a systematic diagnostic approach can help with identifying the underlying etiology and informing treatment strategies. It can be due to cutaneous inflammation, sequelae of inflammatory or infectious dermatoses, or dermatologic procedures. Therefore, a thorough understanding of the epidemiology, patient history, physical exam findings, and clinical features of post-inflammatory hypopigmentation phenomenon can explain the primary cause to providers and allow for patient education. It is also important to understand the various therapeutic approaches available and the efficacy of these options, which will inform providers to choose the appropriate therapy for patients. Although algorithms exist for classifying acquired disorders of hypopigmentation, there are no established algorithms for the diagnosis and treatment of post-inflammatory hypopigmentation, which warrants further exploration and discourse.

A Diagnostically Challenging Case of De Novo Febrile Ulceronecrotic Mucha-Habermann Disease with Fatal Pulmonary Involvement: A Case Report.

The febrile ulceronecrotic Mucha-Habermann disease is a rare and potentially lethal variant of pityriasis lichenoides et varioliformis acuta (PLEVA). It is characterized by a sudden onset of ulceronecrotic skin lesions associated with high fever and systemic symptoms. Herein, we report a 23-year-old male, not known to have any medical illnesses, presented with a month-long history of persistent fever of unknown origin associated with a sudden onset of progressive diffuse necrotic ulcers and widespread papulosquamous lesions. Pan CT showed enlarged lymph nodes in the cervix, chest, and abdomen. Unfortunately, a skin biopsy was done late, showing features consistent with PLEVA. Few days after admission, despite being on intravenous methylprednisolone, our patient rapidly deteriorated by showing severe acute respiratory symptoms and consequently died. In spite of the continuous addition of new case reports to the literature, no definite diagnostic criteria have been established, leading to late or missed cases, and an optimum treatment is still waiting.

Pityriasis Lichenoides Following SARS-CoV-2 Infection/Vaccination.

Purpose of Review: Pityriasis lichenoides (PL) is a spectrum of dermatological conditions involving polymorphous lesions. Natural history of the condition ranges from acute to chronic. Cases of PL following SARS-CoV-2 infection/vaccination have been reported, but not yet comprehensively reviewed. Hence, the objective of this article is to review and summarize cases of PL following SARS-CoV-2 infection/vaccination in order to guide clinicians in its diagnosis and management. Recent Findings: PubMed, Embase, and Web of Science were searched for relevant articles. Thirteen articles, consisting of 14 cases of PL following SARS-CoV-2 infection/vaccination, were identified. Males represented 64.3% of cases, and the average age of those affected was 41.4 years. The majority of cases (N = 9, 64.3%) were following SARS-CoV-2 vaccination, the most commonly implicated being Pfizer-BioNTech (n = 8/10, 80%), while four (28.6) followed infection. The overall latency period ranged from 5 days to 1 month. Treatments varied greatly. However, at the time of follow-up, 12/14 patients (85.7%) had either marked improvement or complete resolution of lesions. Summary: This review cannot determine causality. However, a temporal association was observed with the case reports, and one case of PL followed SARS-CoV-2 infection and recurred with subsequent vaccination, suggesting an association. Nevertheless, risk of developing PL following SARS-CoV-2 infection/vaccination is likely extremely low. There is also the possibility these cases are purely coincidental. Still, clinicians should be aware of this possible etiology when diagnosing a new or exacerbated case of PL. Finally, given that the majority of patients had marked improvement or complete resolution of lesions at the time of follow-up, clinicians should provide reassurance to their affected patients.

Pitiriasis liquenoide varioliforme aguda posterior al inicio de eritropoyetina / Acute varioliform lichenoid pityriasis following the initiation of erythropoietin

Resumen La pitiriasis liquenoide varioliforme aguda (PLEVA) pertenece a un grupo de enfermedades categorizadas como pitiriasis liquenoides, junto con la enfermedad febril úlcero-necrótica de Mucha-Habermann y la pitiriasis liquenoide crónica (PLC). Se caracteriza por la aparición aguda de múltiples pápulas eritemato-violáceas con posterior necrosis, discromía residual y cicatrices varioliformes. Dentro de las teorías patogénicas propuestas se encuentra el posible papel de agentes infecciosos, trastornos linfoproliferativos, complejos inmunes e incluso, asociación a medicamentos. Se presenta un casode una mujer adulta con un cuadro típico de PLEVA con confirmación histopatológica, cuyas lesiones aparecieron posteriormente al inicio de eritropoyetina.

Abstract Pityriasis lichenoides et varioliformes acuta (PLEVA) is part of a group of diseases clustered as pityriasis lichenoides, next to febrile ulceronecrotic Mucha-Habermann disease and pityriasis lichenoides chronica. It's characterized by a sudden onset of multiple erythematous and violaceous papules which develop necrosis, leaving residual dyschromia and varioliform scars. It's been hypothesized the possible role of infectious agents, lymphoproliferative diseases, immune complexes and drugs. We present the case of a woman with a typical PLEVA with histopathological confirmation, whose lesions appeared after therapy with erythropoietin.

A case of febrile ulceronecrotic Mucha-Habermann disease responsive to systemic corticosteroids.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a rare, potentially fatal subtype of pityriasis lichenoides et varioliformis acuta (PLEVA). Herein, we present a rare case of a 14-year-old male without significant past medical history who was diagnosed with FUMHD without a clear inciting factor. He was effectively treated with systemic corticosteroids with complete resolution of symptoms.

The role of NLRP1 and NLRP3 inflammasomes in the etiopathogeneses of pityriasis lichenoides chronica and mycosis fungoides: an immunohistochemical study.

Mycosis fungoides (MF) is the most common subtype of primary cutaneous T cell lymphomas, whereas pityriasis lichenoides chronica (PLC) is a chronic inflammatory skin disorder. The inflammasome is a part of the natural immune system which has a multimeric structure consisting of the receptor, adaptor and effector protein that show specificity for various ligands or activators. After the activation of the inflammasome complex, caspase 1 becomes activated which subsequently triggers interleukin-18 (IL-18) and interleukin-1ß (IL-1ß) production. In our study we aimed to examine the roles of nucleotide-binding oligomerization domain-like receptor containing pyrin domain 1 (NLRP1) and nucleotide-binding oligomerization domain-like receptor containing pyrin domain (NLRP3) inflammasomes in the etiopathogeneses of PLC and MF. NLRP1, NLRP3, caspase 1, IL-18 and IL-1ß levels were examined and compared immunohistochemically in the skin biopsies belonging to 16 control patients; 16 PLC cases, 12 cases with stage 1 MF and 12 cases with other stages of MF (stage 2-4). In the paired comparisons of NLRP1, stage 2-4 MF group and PLC group were shown to have increased levels of NLRP1 expression compared to the control group. IL-1ß was also expressed at statistically significantly higher levels in each of the stage 1 MF, stage 2-4 MF and PLC groups compared to the control group. In the paired comparisons of caspase 1 and IL-18, it was found that stage 1 MF, stage 2-4 MF and PLC groups had increased levels of expression compared to the control group. Our findings suggest that the NLRP1 inflammasome pathway might play a role in the etiopathogenesis and progression of PLC and MF.

Role of streptococcal infection in the etiopathogenesis of pityriasis lichenoides chronica and the therapeutic efficacy of azithromycin: a randomized controlled trial.

The exact aetiology of pityriasis lichenoides chronica (PLC) remains unknown. While phototherapy is the most investigated therapeutic modality, azithromycin has been used scarcely. The aim of this study is to evaluate the therapeutic efficacy of azithromycin in the treatment of PLC compared to NB-UVB and evaluating the presence of streptococcal infection as a possible etiological factor in PLC patients. The study was designed as a randomised controlled trial. Twenty-four patients with PLC were randomly allocated into either azithromycin (n = 13, standard dose every 10 days) or NB-UVB (n = 11, thrice weekly) groups. End of study (EOS) was either complete clearance of lesions or a maximum of 8 weeks. Therapeutic efficacy was defined as percent reduction in lesions and was calculated for the rash as a whole, erythematous papules alone, and hypopigmented lesions alone and graded into complete, very-good, good, poor or no response. Anti-streptolysin O titre (ASOT), anti-deoxyribonuclease B titre (anti-DNaseB) and throat culture were evaluated at day 0. No significant difference existed between both groups as regards therapeutic efficacy. At EOS, NB-UVB achieved significantly more percent reduction in the extent of hypopigmented lesions and consequently in the rash as a whole (p = 0.001, p = 0.034, respectively). The extent of the rash as a whole was significantly less in the NB-UVB at EOS (p = 0.029, respectively). The effect of NB-UVB on hypopigmented lesions appeared early at week 4 of treatment. Only two patients, one from each group, relapsed during the 3 month follow-up. Evidence of recent streptococcal infection was present in 79% of the cases, mainly in the form of elevated ASOT (94.7%). It was significantly more encountered in young children (< 13 years) (p = 0.03) and was associated with more extent of erythematous papules and consequently with more extent of the rash as a whole (p = 0.05 and p = 0.01, respectively). It did not affect outcome of therapy at EOS. Azithromycin did not show more favorable response in patients with recent streptococcal infection. Therapeutic efficacy of azithromycin is comparable to NB-UVB in treatment of PLC; however, NB-UVB is superior in management of hypopigmented lesions. It is highly suggested that PLC could be a post streptococcal immune mediated disorder.Registration number: ClinicalTrials.gov, NCT03831269.