An atypical form of pediatric pityriasis rosea of the diaper area: Pityriasis marginata et circinata of Vidal.

Pityriasis rosea is a common, self-limited disease which in its typical form should not raise diagnostic doubts. Nevertheless, its atypical presentations can be a challenge for the clinician, and hence it is important to be aware of them. Recognition of these forms may enable a correct diagnosis to be made and avoid unnecessary procedures. We present two patients for whom we believe atypical PR was the most likely the diagnosis.

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.

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.

Manifestation of pityriasis rosea and pityriasis rosea-like eruptions after Covid-19 vaccine: A systematic review.

BACKGROUND: After introducing Covid-19 vaccines, a few side effects were reported, pityriasis rosea being one of them. Therefore, this study will systematically review its manifestation afteradministration. METHODS: Databases were searched, covering a timeline from December 1, 2019 to February 28, 2022. Data were independently extracted and accessed for bias. SPSS statistical software version 25 was used for appropriate inferential statistics. RESULTS: Thirty-one studies were included for data extraction after screening following the eligibility criteria. A total of 111 people were identified to have developed pityriasis rosea or pityriasis rosea-like eruptions after vaccination, out of which 36 (55.38%) were female. The average age of incidence was calculated to be 44.92 years, and 63 (62.37%) people presented after administration of the first dose. It was found popularly in the trunk area, either asymptomatically or with mild symptoms. Meantime the onset, was 8.58 days, and meantime it took to recover, was 6.44 weeks. CONCLUSION: The association between pityriasis rosea and pityriasis rosea-like eruptions after Covid-19 vaccines was established, but given the scarcity of studies, there is a need to conduct different clinical trials to confirm this association further and study the etiology and mechanism of the disease.

Impact of COVID-19 on Clinicopathological Spectrum of Pityriasis Rosea in Korea.

BACKGROUND: Pityriasis rosea (PR) is a papulosquamous eruption with generally unknown origin but suspected to be related to viral etiologies. The clinicopathological spectrum of several disorders with viral etiologies has been altered after the coronavirus disease 2019 (COVID-19) pandemic. The author group could experience coherent histological alterations in PR after the COVID-19 pandemic. This study aimed to investigate how the clinicopathological findings of PR were changed after the COVID-19 pandemic. METHODS: Patients (n = 11) diagnosed with PR based on the clinical manifestations and skin biopsies between February 2018 and October 2019 and 11 patients in February 2020 and October 2021 were retrospectively analyzed by investigating the medical records. RESULTS: The patients with PR during the COVID-19 pandemic demonstrated statistically significant histopathological alterations from classic brisk and dense infiltration pattern to dormant and sparse infiltration and psoriasiform-dominant patterns (P = 0.019). PR was associated with more frequent pruritus during the pandemic period (P = 0.027). CONCLUSION: In conclusion, PR demonstrated a significant histopathological alteration with more frequent pruritus during the COVID-19 pandemic. The comparative results about clinicopathological findings of PR will provide a useful reference for dermatologists in the diagnostic process of PR in the COVID-19 pandemic.

Pityriasis rosea in pregnancy: A case series and literature review.

BACKGROUND AND OBJECTIVE: Pityriasis rosea (PR), a common skin disease in young adults, may adversely affects the course of pregnancy and the unborn child. PATIENTS AND METHODS: Data from forty-six pregnant women with PR seen in the dermatological university clinic between 2003 and 2018 were analyzed and compared with patient data (n = 53) from previously published studies to determine the incidence and risk factors for an unfavorable pregnancy outcome after PR infection. RESULTS: Unfavorable pregnancy outcomes (defined as miscarriage, preterm delivery before week 37 of gestation, or birth weight < 2,500 g) were significantly less frequent in our study population than in a pooled cohort obtained from previously published studies (10.9 % vs. 39.6 %; P = 0.0012). Analysis of pooled data from our study and from previous studies revealed that the week of pregnancy at onset of PR was inversely associated with an unfavorable outcome (odds ratio [OR] = 0.937; 95 % CI 0.883 to 0.993). In addition, duration of PR (OR = 1.432; 95 % CI 1.129 to 1.827), additional extracutaneous symptoms (OR = 4.112; 95 % CI 1.580 to 10.23), and widespread rash distribution (OR 5.203, 95 % CI 1.702 to 14.89) were directly associated with unfavorable outcome. CONCLUSION: In most cases, PR does not influence pregnancy or birth outcomes.

Papulosquamous annular diseases.

Papulosquamous diseases represent a commonly encountered group of cutaneous disorders in dermatology. Lesions can present with papules and plaques in various configurations, including annular forms. Some of these disorders are expected to appear in annular configurations, such as pityriasis rosea and subcorneal pustular dermatosis. Others may either begin as or even progress to annular configurations, including psoriasis vulgaris, seborrheic dermatitis, and nummular dermatitis. We have reviewed common papulosquamous diseases that can present with annular lesions, which includes psoriasis vulgaris, pityriasis rosea, subcorneal pustular dermatosis, contact dermatitis, seborrheic dermatitis, and nummular dermatitis. For each disorder, we have discussed the details of presentation and differential diseases to be considered.