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.

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.

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.

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.

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 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.

Next-generation sequencing confirms T-cell clonality in a subset of pediatric pityriasis lichenoides.

BACKGROUND: Pityriasis lichenoides (PL) is a papulosquamous disease that affects both adults and children. Previous studies have shown a subset of this entity to have clonal T-cell populations via PCR-based assays. In this study, we sought to implement next-generation sequencing (NGS) as a more sensitive and specific test to examine for T-cell clonality within the pediatric population. METHODS: We identified 18 biopsy specimens from 12 pediatric patients with clinical and histopathologic findings compatible with PL. Patient demographics, clinical features, management, and histopathologic findings were reviewed. All specimens were analyzed for clonality with NGS of T-cell receptor beta (TRB) and gamma (TRG) genes. RESULTS: Of the 12 patients, 9 (75%) had complete resolution of lesions at the time of data collection (mean follow-up 31 months). The remaining three patients significantly improved with methotrexate (with or without acitretin). Interestingly, 7 of 12 patients (58%) and 9 of 17 biopsy specimens (53%) showed evidence of T-cell clonality. Two patients showed matching TRB clones from different anatomic sites. CONCLUSIONS: T-cell clonality is a common finding in PL, probably representing a "reactive clonality" rather than a true lymphoproliferative disorder. Clonality alone cannot be used as a means to distinguish PL from lymphomatoid papulosis or cutaneous lymphoma.

Hypopigmented lesions in pityriasis lichenoides chronica patients: Are they only post-inflammatory hypopigmentation?

BACKGROUND/OBJECTIVES: Pityriasis lichenoides chronica (PLC) lesions are reported to subside with post-inflammatory hypopigmentation (PIH); hence, the most widely perceived nature of hypopigmented macules in PLC is PIH. However, to the best of our knowledge, no studies describing histopathological findings in these lesions are reported in literature. The aim of this study is to evaluate the hypopigmented lesions encountered in PLC patients and to shed light on their histopathological features. METHODS: A cross-sectional observational study included twenty-one patients with PLC recruited in a period of twelve months. Clinical characteristics of each patient were collected. A skin biopsy from hypopigmented lesions whenever present was taken and assessed with routine haematoxylin and eosin stain. RESULTS: Seventeen patients (81%) were less than 13 years old. Most patients (85.7%) demonstrated diffuse distribution of lesions. Hypopigmented lesions were present on the face in 12 (57.14%) patients. Histopathologically, hypopigmented lesions showed features of post-inflammatory hypopigmentation in 19% of patients, residual PLC in 52.4% and active PLC 28.6% of patients. CONCLUSION: Hypopigmented lesions in PLC were noted mainly in younger ages, histopathologically they may show features of active or residual disease, beyond post-inflammatory hypopigmentation. Consequently active treatment for patients presenting predominantly with hypopigmented lesions could be required to control the disease.

Dermoscopic characterization of guttate psoriasis, pityriasis rosea, and pityriasis lichenoides chronica in dark skin phototypes: An observational study.

Dermoscopy as a diagnostic tool is attaining impetus in inflammatory dermatoses with the cumulative description of characteristic findings in most dermatoses obviating at times the need of biopsy. In this retrospective observational study, 20 histopathology confirmed cases each of pityriasis rosea (PR), guttate psoriasis (GP), and pityriasis lichenoides chronica (PLC) seen over a period of 3 years were included. Dermoscopy images were extracted from photography archives for evaluation and three lesions from each patient (60 lesions each) were analyzed. Comparison of dermoscopy characters was done among PR, GP, and PLC in pairs using chi-square test and a P-value of less than .05 was considered significant. Most common background color in PR (86.7%) and PLC (96.7%) was yellow to yellow-orange and in GP was dull red to pink (70%). Vessels were visualized in all lesions of GP and most characteristic pattern was regular (93.3%), dotted vessels (95%). In PR 63.3% lesions had dotted vessels mostly in a patchy distribution (56.7%). Most prominent scale color in PR was yellow-white (88.3%) and in GP was white-gray (80%). In PLC varying colors were seen, most prominent being brown (53.3%). Characteristic findings seen only in PLC were hypopigmented areas (13.3%), brown dots and globules (53.3%) and orange-yellow structureless areas (61.7%) GP, PR, and PLC reveal specific dermoscopic findings that can help in differentiating them. Further, the known dermoscopic criteria for GP, PR, and PLC also apply for dark skin phototypes.

Histopathologic features distinguishing secondary syphilis from its mimickers.

BACKGROUND: Syphilis is often misdiagnosed clinically, and biopsies might be required. OBJECTIVE: To determine histopathologic features that distinguish secondary syphilis from pityriasis lichenoides (PL), pityriasis rosea (PR), and early mycosis fungoides (MF). METHODS: Histopathologic features of 100 cases of syphilis, 110 cases of PL, 72 cases of PR, and 101 cases of MF were compared. RESULTS: Elongated rete ridges and interstitial inflammation favor syphilis over PL (likelihood ratios 3.44 and 2.72, respectively), but no feature reliably distinguishes between them. Secondary syphilis and PR can be distinguished by neutrophils in the stratum corneum, plasma cells, interface dermatitis with lymphocytes and vacuoles, and lymphocytes with ample cytoplasm. Plasma cells and lymphocytes with ample cytoplasm are rare in early MF and can be used as distinguishing features. CONCLUSIONS: Histopathologic features characteristic of syphilis can be seen in PL, PR, and early MF. Distinguishing syphilis from PL can be difficult histologically, and a high index of suspicion is required. Although elongation of rete and interstitial inflammation favor syphilis, plasma cells (historically considered a significant feature of syphilis) are often encountered in PL. Vacuolar interface dermatitis with a lymphocyte in every vacuole is considered characteristic of PL, but this feature appears to be more common in syphilis.

Oral erythromycin in pityriasis lichenoides chronica and pityriasis lichenoides et varioliformis acuta.

Pityriasis lichenoides (PL) is an uncommon cutaneous disorder. Oral erythromycin is proposed to be effective in treating the disease. Here, we reported 16 pediatric patients with PL and systematically reviewed published literatures on erythromycin treatment response in pediatric PL patients, to observe the different treatment response to erythromycin in the pityriasis lichenoides chronica (PLC) and the pityriasis lichenoides et varioliformis acuta (PLEVA) groups. Sixteen patients, 8 with PLC and 8 with PLEVA, were treated with erythromycin. In the PLC group, 25% (n = 2) patients responded to erythromycin, while in the PLEVA group, 87.5% (n = 7) patients responded to erythromycin. The response rate was higher in the PLEVA group than the PLC group (P =.05). No side effect was reported in the 16 patients. A total of 34 children including 16 from our studies were included for further descriptive analysis, in which 12 had PLC and 22 had PLEVA. In the PLC group, 41.7% (n = 5) of patients responded to erythromycin while in the PLEVA group, 90.9 % (n = 20) of patients responded. The response rate was higher in the PLEVA group than the PLC group (P = .004). In conclusion, erythromycin is effective and safe in the treatment of children with PL, and erythromycin was more effective in patients with PLEVA than PLC.

Poikilodermatous Mycosis Fungoides: Comparative Study of Clinical, Histopathological and Immunohistochemical Features.

BACKGROUND: Poikilodermatous mycosis fungoides (pMF) is characterized by poikiloderma areas, typically involving the major flexural areas and trunk. Its presentation can be generalized or admixed with other forms of MF. Previous studies fail to correlate the clinical presentation with prognosis and laboratory findings. Some reports show pityriasis lichenoides chronica (PLC) preceding the poikiloderma. OBJECTIVES: Correlate prognostic, histopathological and molecular aspects of pMF with its clinical presentation. METHODS: Retrospective analysis of 14 cases of generalized pMF (GpMF), 22 of localized pMF (LpMF) and 17 of pMF admixed with other forms of MF (mix-pMF). RESULTS: Female predominance and lower age at diagnosis was found in all groups compared to classic MF, a high prevalence of PLC-like lesions in the GpMF group and a high rate of hypopigmented lesions in the mix-pMF group. There were 2 deaths within the GpMF group. Histology was similar to previously reported findings, as was the prevalence of CD4 T-cell infiltrate, compared to CD8. The T-cell clonality positivity was lower in the GpMF group, compared to other groups (27% GpMF, 80% LpMF and 100% mix-pMF). DISCUSSION: This is the first article to categorize the different forms of pMF and correlate them with clinical and laboratory findings. The dermatological presentation differs among the groups. There was a high frequency of PLC-like lesions within the GpMF group and of hypopigmented lesions in mix-pMF. The histological and immunohistochemical findings were similar to those previously reported. Aggressive treatments are not recommended due to the good prognosis of all pMF forms. The low positivity of T-cell clonality in the GpMF group should be investigated.

Pityriasis lichenoides acuta (PLEVA) pemphigoides: A rare bullous variant of PLEVA.

Although the clinical presentations of patients with pityriasis lichenoides et varioliformis acuta (PLEVA) may vary, bullae are not usually part of the clinical spectrum. To date, only two other cases of a bullous variant of PLEVA with evidence of autoantibodies against hemidesmosomal antigens have been reported. The term PLEVA pemphigoides was suggested for this unique clinical, pathological and serological combination of both PLEVA and bullous pemphigoid.

A case of pityriasis lichenoides et varioliformis acuta pemphigoides successfully treated with methotrexate and corticosteroids.

Pityriasis lichenoides et varioliformis acuta (PLEVA) pemphigoides is an uncommon skin disease, which is characterized by the appearance of blistering skin lesions in patients with PLEVA. We present a 3-year-old boy, who was diagnosed with PLEVA pemphigoides. Combined treatment of oral methotrexate and corticosteroids was more effective than corticosteroids alone on this patient.

A case of pityriasis lichenoides: Rapid resolution with azithromycin monotherapy in 3 weeks.

Pityriasis lichenoides (PL) is a spectrum of inflammatory skin diseases which include PL et varioliformis acuta (PLEVA) and PL chronica (PLC) as two ends of the disease and rarely both entities can coexist on the same patient. Treatment options are based on case series-reports, and anecdotes, and include topical corticosteroids, topical immunomodulators, systemic antibiotics (tetracycline, erythromycin), and phototherapy. Herein, we report a 13-year-old boy, exhibiting mixed manifestations of PLEVA and PLC lesions concurrently, with a rapid and dramatic response to azithromycin monotherapy.

Pityriasis lichenoides: Long-term follow-up study.

BACKGROUND/OBJECTIVES: Pityriasis lichenoides is an uncommon papulosquamous disorder of unknown etiology. The objective of this study was to review the clinical features and treatment responses of individuals with pityriasis lichenoides seen at a tertiary referral center. METHODS: Seventy-five patients diagnosed with pityriasis lichenoides between 1997 and 2013 were reviewed, and 46 had long-term follow-up via telephone interviews. RESULTS: Fifty (67%) patients were diagnosed with pityriasis lichenoides chronica, 22 (29%) with pityriasis lichenoides et varioliformis acuta, and 3 (4%) with mixed pityriasis lichenoides chronica and pityriasis lichenoides et varioliformis acuta features. Mean ± standard deviation age at onset was 12 ± 13 years (median 8 years). Disease duration was significantly shorter for patients with pityriasis lichenoides et varioliformis acuta (35 ± 35 months) than for those with pityriasis lichenoides chronica (at least 78 ± 48 months). At long-term follow-up, 23 of 28 (82%) patients with pityriasis lichenoides chronica and 3 of 16 (19%) with pityriasis lichenoides et varioliformis acuta had active disease. None progressed to lymphomatoid papulosis or cutaneous T-cell lymphoma. Ten of 23 active pityriasis lichenoides chronica cases had residual pigmentary change independent of race and lasted at least 35 ± 20 months. The most effective treatments were phototherapy (47% response rate), heliotherapy (33%), topical corticosteroids (27%), and antibiotics (25%). CONCLUSION: Pityriasis lichenoides is a predominantly pediatric disorder. The time course of pityriasis lichenoides chronica is significantly longer than that of pityriasis lichenoides et varioliformis acuta. Pityriasis lichenoides chronica may persist with pigmentary alterations in the absence of other signs of active inflammation. Treatment response is often limited, particularly for patients with pityriasis lichenoides chronica.