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.

Pitiriasis liquenoide crónica en un adulto mayor: reporte de un caso / Pityriasis lichenoides in an older adult: report of a case

La pitiriasis liquenoide crónica (PLC) es una enfermedad benigna, que se caracteriza por tener un curso gradual, con aparición de múltiples pápulas con escamas adherentes de predominio en tronco y extremidades proximales. Con el objetivo de describir la presentación clínica, discutir el diagnóstico, diagnósticos diferenciales, tratamiento y revisar la literatura se presenta el caso de un hombre de 88 años que presentó múltiples lesiones papuloescamosas en extremidades inferiores. Se realizó biopsia cutánea que confirmó el diagnóstico de PLC. El paciente recibió tratamiento con emulsión hidratante, clobetasol tópico y claritromicina con resolución completa de las lesiones. La pitiriasis liquenoide crónica es un trastorno inflamatorio poco frecuente, de etiología desconocida que ocurre más comúnmente en adultos jóvenes y niños. Si bien la clínica es sugerente, se requiere biopsia cutánea para su confirmación diagnóstica. Es un trastorno benigno, a menudo asintomático y autolimitado, por lo que se debe valorar su tratamiento paciente a paciente. Principalmente se utilizan corticoides tópicos y antibióticos orales (tetraciclinas y eritromicina). Se ha vinculado en escasas publicaciones con el desarrollo de linfoma cutáneo y como síndromes paraneoplásicos, por lo que se sugiere realizar seguimiento.

Chronic lichenoid pityriasis (PLC) is a benign disorder, characterized by a gradual course with the appearance of multiple squamous papules with adherent scales predominating in the trunk and proximal extremities. With the objective to describe its clinical presentation, diagnosis, differential diagnosis, treatment and review literature, we present an 88-yearold male with multiple lesions in the lower extremities of one year of evolution, with papules and adherent scales. A skin biopsy was performed that confirmed the diagnosis of PLC. The patient received treatment with moisturizing emulsion, clobetasol topical and clarithromycin with complete resolution of the lesions. Chronic lichenoid pityriasis is a rare inflammatory disease of unknown etiology that occurs most commonly in young adults and children. Although the clinic is suggestive, a skin biopsy is required for diagnostic confirmation. It is a benign disorder, often asymptomatic and self-limiting, so its patientto- patient treatment should be assessed. Topical corticosteroids and oral antibiotics (tetracyclines and erythromycin) are used. It has been linked in few publications with the development of cutaneous lymphoma and as paraneoplastic syndromes, so it is suggested to follow up.

Pitiriasis liquenoide: presentación de un caso clínico y revisión de la literatura / Pityriasis Lichenoides: Case report and review of the literature

Introducción: La pitiriasis liquenoide es una enfermedad inflamatoria benigna de causa desconocida. Tiene dos formas de presentación: una forma aguda (PLEVA, pitiriasis liquenoide y varioliforme aguda) y otra crónica (PLC, pitiriasis liquenoide crónica). Ambas son más frecuentes en niños y adultos jóvenes. Objetivo: Describir un caso de PLC, comentar su presentación clínica, diagnóstico y tratamiento, y revisar la literatura. Caso clínico: Escolar de 7 años que presentó episodios recurrentes de lesiones tipo pápulas eritematocostrosas brillantes de distribución centrípeta, oligosintomáticas, que desaparecían dejando máculas hipopigmentadas. La biopsia de las lesiones confirmó una pitiriasis liquenoide crónica. Durante los 3 años de seguimiento se realizaron múltiples esquemas de tratamiento para atenuar las reagudizaciones, logrando una respuesta parcial. Conclusión: La PLC es una enfermedad infrecuente que representa un desafío diagnóstico y terapéutico para el médico. El diagnóstico de esta entidad se sospecha por la clínica y se confirma con la histología. No tiene tratamiento específico pero presenta buena respuesta a corticoides, antibióticos, inmunosupresores y fototerapia UVB de banda angosta (UVB-nb). Esta última es la que ha reportado los mejores resultados. Es importante el seguimiento de los pacientes por el riesgo de desarrollar enfermedades linfoproliferativas.

Introduction: Pityriasis lichenoides is a benign inflammatory disease of unknown etiology. There are two types of this condition: an acute form (PLEVA = pityriasis lichenoides et varioliformis acuta) and a chronic one (PLC = pityriasis lichenoid chronica). Both are more common in children and young adults. Objective: To describe a case of PLC, discuss its clinical presentation, diagnosis, treatment and present a review of the literature. Case Report: A seven-year-old child who presented with recurrent oligosymptomatic episodes of bright erythematous papular lesions in centripetal distribution, which subsided and left behind hypopigmented macules. The biopsy of the lesions confirmed chronic pityriasis lichenoid. During the 3 years of follow-up, multiple treatment regimens were used to reduce exacerbations, resulting in a partial response. Conclusion: PLC is a rare disease that represents a diagnostic and therapeutic challenge to the physician. The diagnosis of this condition is suspected clinically and confirmed by histology. It does not have specific treatment, but it responds well to corticosteroids, antibiotics, immunosuppressants and phototherapy with UVB narrowband (UVBnb). The latter has given the best results. It is important to monitor patients for risk of developing lymphoproliferative disorders.

Doença de Mucha-Habermann / Mucha-Habermann disease

Os autores descrevem um caso de doença de Mucha-Habermann (DMH), que cursou com quadro sugestivo de síndrome de ativação macrofágica (SAM). O objetivo do trabalho foi descrever um caso de rara vasculite de Mucha-Habermann (pitiríase liquenoide e varioliforme aguda - PLEVA) em paciente de 28 anos que apresentou lesões ulceronecróticas generalizadas em pele e mucosas, acometimento gastrointestinal, cardíaco e hepático, associados a febre alta contínua, com provável evolução para SAM e posterior óbito. Trata-se de doença rara, potencialmente fatal, com graves complicações sistêmicas. Os autores ressaltam a importância de seu diagnóstico e de tratamento agressivo.

A case of Mucha-Habermann disease (MHD), possibly associated with macrophage activation syndrome (MAS), is reported. The purpose of this paper was to describe the rare MHD (also known as pityriasis lichenoides et varioliformis acuta - PLEVA) in a 28-year-old male, who presented with generalized ulceronecrotic lesions on the skin and mucosae, gastrointestinal involvement, and heart andliver failure, associated with continuous high fever.The patient might have progressed to MAS and eventually died. The MHD is rare, potentially fatal and has severe systemic complications.The importance of early diagnosis and aggressive treatment is emphasized.

Haga su diagnóstico / Make your diagnosis

El diagnóstico es Pitiriasis liquenoide crónica

Pitiriasis liquenoide: descripción de un caso / Pityriasis lichenoides: description of a case

La pitiriasis liquenoide (PL) es una dermatosis inflamatoria adquirida, idiopática, infrecuente, benigna y autoinvolutiva, que tiene dos variantes: aguda y crónica, con base en las diferencias morfológicas, la evolución temporal y el curso de este trastorno. Éstas pueden considerarse como los dos extremos clínicos dentro del espectro de una misma enfermedad. Clínicamente la PL se caracteriza por el desarrollo de brotes recurrentes de pápulas eritemato-descamativas liquenoides, de superficie queratósica, que pueden persistir por semanas o meses (crónica), o bien brotar y recidivar con exacerbaciones agudas acompañadas, frecuentemente, por vésico-pústulas, ulceración, hemorragias y costras (aguda), que curan dejando cicatrices atróficas varioliformes. Presentamos el caso de un escolar de 9 años de edad con una PL con escasas costras hemáticas puntiformes y con máculas hipopigmentadas residuales.

Pityriasis lichenoides (PL) is an inflammatory acquired idiopathic, rare, benign and self-healing dermatosis, which has two variants: acute and chronic, based on morphological differences, evolution and course of the disorder that can be regarded as clinical extremes within the spectrum of the same disease. It is characterized by the development of recurrent outbreaks of scaly erythematous lichenoid papules, with keratotic surface, which can persist for weeks or months (chronic) or sprout with acute exacerbations frequently accompanied by vesico-pustules, ulceration, bleeding and crusting (acute) that heal leaving atrophic varioliformis scars. We report the case of a 9 years old boy who developed pityriasis lichenoides with few punctate hematic crusts and residual hypopigmented macules.