Psoriasiform graft-versus-host disease distributed along Blaschko's lines.

This case presents an unusual manifestation of cutaneous chronic graft-vs-host disease (cGVHD) mimicking psoriasis along Blaschko's lines. Such a presentation may pose a particular challenge to providers as it is quite rarely reported, and, therefore, it is possibly misdiagnosed. cGVHD may mimic psoriasis and should be considered in any patient previously transplanted even with a previous history of psoriasis. A Blaschkoid pattern of cGVHD is unusual and may be the manifestation of an immune reaction unveiling a previously masked mosaicism.

Rare missense variants in the SH3 domain of PSTPIP1 are associated with hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic, debilitating skin disease for which few treatment options are available. While most HS is sporadic, some rare kindred show a high-penetrance, autosomal-dominant inheritance. We wanted to identify rare variants that could contribute to HS risk in sporadic cases using candidate gene sequencing. We ultimately identified 21 genes for our capture panel. We included genes of the γ-secretase complex (n = 6) because rare variants in these genes sometimes cause familial HS. We added Notch receptor and ligand genes (n = 13) because γ-secretase is critical for processing Notch receptor signaling. Clinically, some people with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome, a rare inflammatory disease, have concurrent HS. Rare variants in PSTPIP1 are known to cause PAPA syndrome, so we included PSTPIP1 and PSTPIP2 in the capture panel. We screened 117 individuals with HS for rare variations and calculated the expected burden using Genome Aggregation Database (gnomAD) allele frequencies. We discovered two pathogenic loss-of-function variants in NCSTN. This class of NCSTN variant can cause familial HS. There was no increased burden of rare variations in any γ-secretase complex gene. We did find that individuals with HS had a significantly increased number of rare missense variants in the SH3 domain of PSTPIP1. This finding, therefore, implicates PSTPIP1 variation in sporadic HS and further supports dysregulated immunity in HS. Our data also suggests that population-scale HS genetic research will yield valuable insights into disease pathology.

Development of a Skin-Directed Scoring System for Stevens-Johnson Syndrome and Epidermal Necrolysis: A Delphi Consensus Exercise.

Importance: Scoring systems for Stevens-Johnson syndrome and epidermal necrolysis (EN) only estimate patient prognosis and are weighted toward comorbidities and systemic features; morphologic terminology for EN lesions is inconsistent. Objectives: To establish consensus among expert dermatologists on EN terminology, morphologic progression, and most-affected sites, and to build a framework for developing a skin-directed scoring system for EN. Evidence Review: A Delphi consensus using the RAND/UCLA appropriateness criteria was initiated with a core group from the Society of Dermatology Hospitalists to establish agreement on the optimal design for an EN cutaneous scoring instrument, terminology, morphologic traits, and sites of involvement. Findings: In round 1, the 54 participating dermatology hospitalists reached consensus on all 49 statements (30 appropriate, 3 inappropriate, 16 uncertain). In round 2, they agreed on another 15 statements (8 appropriate, 7 uncertain). There was consistent agreement on the need for a skin-specific instrument; on the most-often affected skin sites (head and neck, chest, upper back, ocular mucosa, oral mucosa); and that blanching erythema, dusky erythema, targetoid erythema, vesicles/bullae, desquamation, and erosions comprise the morphologic traits of EN and can be consistently differentiated. Conclusions and Relevance: This consensus exercise confirmed the need for an EN skin-directed scoring system, nomenclature, and differentiation of specific morphologic traits, and identified the sites most affected. It also established a baseline consensus for a standardized EN instrument with consistent terminology.

Fibrous Proliferations in Posttransplant Kaposi Sarcoma.

Kaposi sarcoma (KS) is characterized by cutaneous lesions that are often papular and present variably depending on the stage of progression. We describe a patient with a fibroma-like nodule, a lesion not commonly associated with KS. Previously observed in lymphedematous human immunodeficiency virus-associated KS, the occurrence of this nodule in the absence of chronic lymphedema suggests an alternative etiology.

Spider Telangiectases and Palmar Erythema as Harbingers of Structural Liver Changes in Three Breast Cancer Patients on Ado-trastuzumab Emtansine.

Objective: We describe three patients treated with ado-trastuzumab emtansine who developed either palmar flushing or spider angiomas. We then correlate these findings with radiologic imaging results of the liver. Design: Three consecutive referrals to dermatology for patient skin complaints while taking ado-trastuzumab emtansine were evaluated and found to have either telangiectases or palmar flushing. Two patients who did not have prominent nodularity on computed tomography of the liver underwent transient elastography. Results: All three patients with stigmata of liver disease that developed during the course of ado-trastuzumab emtansine demonstrated parenchymal liver abnormalities. Conclusion: Patients presenting with spider angiomas and/or palmar flushing on adotrastuzumab emtansine should be considered for elastography studies to ensure early structural damage is not occurring. Further investigation is needed to define the precise etiology for these telangiectases and the role of elastography imaging in monitoring patients on long-term adotrastuzumab emtansine.