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.

What is pityriasis lichenoides?

Pityriasis lichenoides (PL) is an uncommon skin rash. PL has two main forms: Pityriasis lichenoides et varioliformis acuta (PLEVA): this "acute" (fast) form comes on quickly. Pityriasis lichenoides chronica (PLC): this "chronic" (long) form often develops slowly and lasts longer.

Paediatric-onset lymphomatoid papulosis: results of a multicentre retrospective cohort study on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG).

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population are scarce. OBJECTIVES: To characterize the epidemiological, clinical, histopathological and prognostic features of paediatric LyP. METHODS: This was a retrospective multicentre international cohort study that included 87 children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years at disease onset were included. LyP diagnosis was made in each centre, based on clinicopathological correlation. RESULTS: Eighty-seven patients from 12 centres were included. Mean age at disease onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2 : 1. Mean time between the onset of the first cutaneous lesions and diagnosis was 1.3 years (range 0-14). Initial misdiagnosis concerned 26% of patients. LyP was most often misdiagnosed as pityriasis lichenoides et varioliformis acuta, insect bites or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned in 21% of patients. The main histological subtype was type A in 55% of cases. When analysed, monoclonal T-cell receptor rearrangement was found in 77% of skin biopsies. The overall survival rate was 100%, with follow-up at 5 years available for 33 patients and at 15 years for 8 patients. Associated haematological malignancy (HM) occurred in 10% of cases (n = 7/73), including four patients with mycosis fungoides, one with primary cutaneous anaplastic large cell lymphoma (ALCL), one with systemic ALCL and one with acute myeloid leukaemia. If we compared incidence rates of cancer with the world population aged 0-19 years from 2001 to 2010, we estimated a significantly higher risk of associated malignancy in general, occurring before the age of 19 years (incidence rate ratio 87.49, 95% confidence interval 86.01-88.99). CONCLUSIONS: We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall, the disease prognosis is good, with excellent survival rates for all patients. Owing to an increased risk of associated HM, long-term follow-up should be recommended for patients with LyP.

Lymphomatoid papulosis is a very rare skin condition caused by an abnormal increase in white blood cells (called 'lymphocytes') in the skin. The condition rarely affects children, so most of the scientific data published about this disease focuses on adults. This study involved 12 academic dermatology centres in Europe, the Middle East and North America, and gathered data from about 87 children who presented with symptoms of lymphomatoid papulosis before the age of 19 years. The aim of this study was to better describe this disease in the paediatric population and discuss its treatment options and evolution. We found that the presentation of the disease in children is roughly the same as in adults. Safe and effective treatment options exist. The disease is not life threatening, but it requires investigation by a dermatologist, both to make a careful diagnosis and to monitor it as sometimes associated cancers that originate from blood cells can occur, mostly on the skin.

Febrile Ulceronecrotic Mucha-Habermann Disease Associated With Hemophagocytic Lymphohistiocytosis: A Case Report and Review of the Literature.

ABSTRACT: Mucha-Habermann disease (MHD) is an inflammatory skin disease characterized by polymorphous eruptions of erythematous, necrotic macules that have been reported for similarities to cutaneous T-cell lymphoma. Febrile ulceronecrotic MHD (FUMHD) represents a severe variant of MHD, marked by ulcers, hemorrhagic bullae, and systemic symptoms. Herein, we report a case of a severely atypical lymphomatoid expression of FUMHD associated with hemophagocytic lymphohistiocytosis (HLH). A previously healthy 21-year-old woman was admitted to the hospital with a rapidly progressive necrotic papular rash. Physical examination revealed right orbital swelling, bilateral hemorrhagic auricular bullae, and multiple ulcerative purpuric papulonodules on the trunk, face, and extremities. Biopsy indicated a dermal and subcutaneous infiltrate of atypical CD8 + lymphocytes with loss of CD5 and reduction in CD7 expression, along with features of lymphomatoid vasculitis. A diagnosis of a severely atypical lymphomatoid expression of FUMHD was made. The patient also met 7 of 9 HLH-2004 criteria, leading to a diagnosis of HLH. Positron emission tomography/computed tomography, flow cytometry, and rheumatologic workup were unremarkable. Treatment with an eight-week course of etoposide and dexamethasone for HLH led to rapid clinical improvement. Over time, her skin lesions regressed and eventually scabbed over to leave hyperpigmented scars, confirming the diagnosis of MHD. She has remained stable, off therapy for 4 years. Although potentially fatal, FUMHD often exhibits favorable outcomes and may resolve without recurrence, as in our patient. FUMHD should be considered in the differential diagnosis for patients presenting with cutaneous CD8 + necrotizing angiocentric lymphoproliferative disease complicated by HLH.

Atypical plaque psoriasis: a clinicopathological study of 20 cases.

BACKGROUND: Plaque psoriasis is relatively straightforward to identify. When diagnostic concerns arise in atypical cases, a biopsy is needed. It is widely accepted that the Munro microabscess and the spongiform pustule of Kogoj are diagnostic pathological features. However, the diagnostic dilemma is likely to arise in cases without these specific pathological changes and typical clinical features. This study aimed to investigate clinical and pathological clues in distinguishing atypical plaque psoriasis from its mimics. METHODS: We evaluated the clinicopathological features of 20 cases of atypical plaque psoriasis and 40 cases of psoriasis mimics as controls including pityriasis rosea (n = 10), pityriasis lichenoides chronica (n = 8), and subacute dermatitis (n = 22). RESULTS: A retrospective analysis of the clinicopathological characteristics of patients with atypical plaque psoriasis and controls was performed. Pathologically, there were significant differences between the two groups in the types of parakeratosis (P = 0.046), epidermal capture of extravasated erythrocytes (P = 0.011), focal basal liquefied degeneration (P = 0.017), types of inflammatory cells (P = 0.000), and depth of inflammation (P = 0.000). Clinically, we found the presence of scales and crusts was significantly different between the two groups. CONCLUSION: This study offers insight into the clinicopathological features of atypical plaque psoriasis. These differential diagnostic features, compared with its mimics, are proposed to assist the clinician in the diagnosis and treatment of atypical plaque psoriasis.

Dermoscopy as a diagnostic aid in pityriasis lichenoides et varioliformis acuta.

Diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) is based on the characteristic pattern of lesions in different stages of development, ranging from erythematous maculopapules to papules with a crusted and/or necrotic centre. However, it may raise the differential diagnosis with other entities. It is therefore not uncommon to have to perform skin biopsies to reach a diagnosis, including in infants. In this study, we report the cases of three patients with PLEVA, highlighting the correlations between the clinical, dermoscopic and histological features. Observation of the dermatoscopic findings described, such as punctate or glomerular vessels and erythematous globules surrounding a homogeneous orange or crusty central area, may allow for a rapid diagnosis, avoiding the need for invasive techniques.

Acute lichenoid and varioliform pityriasis in a pediatric patient.

BACKGROUND: Pityriasis lichenoides et varioliformis acuta (PLEVA) is a rare dermatosis recognized as a benign condition of unknown etiopathogenesis. It is more common in pediatric patients and young adults and is characterized by multiple small or large erythematous plaques spread over the trunk and extremities. CASE REPORT: We describe the case of a 5-year-old male, previously healthy, with multiple erythematous lesions that disappeared leaving hypopigmented macules. The biopsy reported histological changes suggestive of mycosis fungoides. After a second revision of lamellae in this hospital, lymphocytic vasculitis (LV) with focal epidermal necrosis consistent with acute pityriasis lichenoides (PL) was identified. CONCLUSIONS: The existing knowledge about PLEVA lacks a consensus in specifying its classification, etiopathogenesis, diagnosis, and treatment, so this clinical condition represents a medical challenge. The diagnosis is made by clinical suspicion and confirmed by histology. The objective of this article was to report a case of PLEVA with an atypical presentation due to its histopathological findings, being the first report showing LV in children, as well as a review of the literature.

INTRODUCCIÓN: La pitiriasis liquenoide y varioliforme aguda (PLEVA) es una dermatosis poco frecuente, de etiopatogenia desconocida y evolución autolimitada. Es más común en pacientes pediátricos y adultos jóvenes, y está caracterizada por la presencia de múltiples placas eritematoescamosas pequeñas o grandes, diseminadas en el tronco y las extremidades. CASO CLÍNICO: Se describe el caso de un escolar de 5 años, de sexo masculino, previamente sano, que presentó múltiples cuadros de lesiones eritematosas que desaparecían dejando máculas hipopigmentadas. La biopsia reportó cambios histológicos sugestivos de micosis fungoide. Se realizó una segunda revisión de laminillas, identificando vasculitis linfocítica con necrosis epidérmica focal, consistente con pitiriasis liquenoide aguda. CONCLUSIONES: El conocimiento acerca de la PLEVA carece de un consenso que especifique su clasificación, etiopatogenia, diagnóstico y tratamiento, por lo que esta condición clínica representa un desafío médico. El diagnóstico se realiza por sospecha clínica y se confirma por histología. El objetivo de este artículo fue reportar un caso de PLEVA con presentación atípica por los hallazgos histopatológicos, siendo este el primer reporte de vasculitis linfocítica en niños, y además se realiza una revisión de la literatura.

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.

Febrile Ulceronecrotic Mucha-Habermann Disease: A Case Report and Review of Literature in the Paediatric Population.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a rare fulminant variant of pityriasis lichenoides et varioliformis acuta (PLEVA) that is characterized by a large ulceronecrotic appearance with high fever and a variety of systemic symptoms. We report here a case of FUMHD in a 17-year-old male Chinese patient who was treated successfully with a combination therapy of methotrexate, methylprednisolone, and intravenous immunoglobulin. In addition, a literature review was conducted to summarize the key characteristics of paediatric FUMHD cases.

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.

Type D lymphomatoid papulosis with pityriasis lichenoides et varioliformis acuta-like features in a child with parvovirus infection: a controversial diagnosis in the spectrum of lymphoid proliferations: case report and literature review.

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare condition in pediatrics; LyP histological type D has been reported in only 7 children. The differential diagnosis of LyP in the spectrum of lymphoid proliferation remains controversial. CASE PRESENTATION: A 6-year-old boy presented to Emergency Department with a 3-week history of an erythematous papulo-vesicular itchy eruption over the submandibular regions, trunk and extremities. History, symptoms and laboratory tests were unremarkable. SARS-CoV-2 antigen was negative. The clinical suspicion of pityriasis lichenoides et varioliformis acuta (PLEVA) was posed, and topical steroids were introduced. One week after, he returned with an extensive painful scaly papulo-erythematous rash, with some ulcerated and necrotic lesions, and fever; therefore the child was hospitalized. Biochemical results were within reference limits, except for high level of C-reactive protein, aspartate aminotransferase, alanine transaminase and bilirubin. Due to a persistently high fever, systemic corticosteroid treatment was administered, with a good clinical response and an improvement of the skin lesions. Anti-PVB-19 Immunoglobulin M was detected. Elevated levels of IL-6, IL-10 and IFN-γ were also recorded. Five days post-admission, most of the lesions had cleared, and the child was discharged. Methotrexate was started, with a positive response. At skin biopsy a "PLEVA-like" pattern was apparent, with a dense, wedge shaped lymphoid infiltrate featuring epidermotropism and morphologically comprising pleomorphic and blastic cells. The pattern of infiltration was highlighted by immunohistochemical stains, which prove the process to feature a CD8+/CD30 + phenotype, the latter being intense on larger cells, with antigenic loss. Polymerase chain reaction for T-cell receptor gamma (TCRG) chain clonality assessment documented a monoclonal peak. A diagnosis of LyP type D was favored. CONCLUSION: The reported case encompasses most of the critical features of two separated entities-PLEVA and LyP-thus providing further support to the concept of them representing declinations within a sole spectrum of disease. Studying the role of infectious agents as trigger potential in lymphoproliferative cutaneous disorders and detecting novel markers of disease, such as cytokines, could have a crucial impact on pathogenic disease mechanisms and perspective therapies.

Childhood lymphomatoid papulosis Type D, a rare and challenging diagnosis.

A 10-year-old female with a several-year history of pityriasis lichenoides (PL) presented with a new, asymptomatic, large, and necrotic ulcer of her right upper arm. Skin biopsy was consistent with lymphomatoid papulosis (LyP) Type D, a recently recognized subtype of LyP that is distinguished histologically by marked epidermotropism and a perivascular infiltrate of medium-sized pleomorphic lymphocytes with a cytotoxic phenotype (CD3+, CD8+). This is only the sixth reported case of LyP Type D in a child, and while the prognosis in children appears favorable, with no reports of progression to lymphoma to date, more experience in children with longer-term follow-up is needed. Our case highlights both the challenging clinical diagnosis, since in our patient the longstanding clinical presentation was indistinguishable from PL, as well as histopathologic diagnosis, which required expert opinion and consensus.

Pityriasis Lichenoides Chronica in a Patient With Ankylosing Spondylitis Treated With Etanercept.

Pityriasis lichenoides is a scarce cutaneous disorder with unknown etiology. It contains a range of clinical manifestations including acute papular lesions that quickly grow into pseudo vesicles and central necrosis to small, scaling, benign-appearing papules.1,2.

Pityriasis Lichenoides Chronica in a Patient With Ankylosing Spondylitis Treated With Etanercept.

BACKGROUND: Pityriasis lichenoides chronica, a papulosquamous disorder often considered a subtype of pityriasis lichenoides. It is considered a clonal T-cell disorder, which may be associated with cutaneous T-cell lymphoma that may develops in response to foreign antigens. CASE PRESENTATION: We present a 38-year-old male patient with ankylosing spondylitis who was on treatment with etanercept. After 8 weeks of treatment, the patient presented with scaly erythematous papules, on the back and arms. He was diagnosed clinically with pityriasis lichenoides chronica. CONCLUSION: Pityriasis lichenoides chronica should be included among the broad clinical spectrum of chronic inflammatory skin diseases which may occur during treatment with TNF-alpha antagonists. J Drugs Dermatol. 2020;19(5): doi:10.36849/JDD.2020.2191.