title: Epidemiologic, Clinicopathologic, Diagnostic, and Management Challenges of Pityriasis Rubra Pilaris: A Case Series of 100 Patients.
abstract: Pityriasis rubra pilaris (PRP) is a rare papulosquamous disorder with limited epidemiologic and clinicopathologic data. Little information is available on long-term outcomes, comorbidities, and treatment efficacy.
  
  
  
  To evaluate objective and subjective disease experience metrics from the perspectives of patients and clinicians.
  
  
  
  One hundred patients with a putative diagnosis of PRP and who elected to participate completed a comprehensive survey, followed by acquisition of their medical records, including histopathology slides and reports. The data were analyzed separately from the health care clinician and the patient perspectives. Two academic dermatologists examined clinical notes, pathology reports, and photographs, confirming diagnoses via predetermined criteria. Patients were categorized into 4 levels of diagnostic certainty to allow stratification of the findings for subgroup analysis. Patients with a diagnosis of PRP were solicited through patient support organization websites.
  
  
  
  Clinical outcomes, unexpected association of comorbidities, and efficacy (or lack of it) of various treatment modalities.
  
  
  
  Among the 100 patients, 50 were diagnosed as having classic, unquestionable PRP. The patients were a median of 61 years old (range, 5-87 years), and 46% were female. Fifty were categorized as level 1 diagnostic certainty, 15 as level 2, 30 as level 3, and 5 as level 4. Of the level 1 patients, 13 (26%) were correctly diagnosed at initial presentation; diagnosis was delayed, on average, by 29 months (range, 0.25-288 months; median, 2 months); and 27 (54%) having undergone 2 or more biopsies. At enrollment, PRP symptoms had persisted in 36 patients (72%) for an average of 58 months (range, 1-300 months; median, 30 months). Thirty-one patients (62%) had comorbidities, including hypothyroidism (20%). Nearly all patients (98%) received some form of therapy. Patients cited topical emollients, corticosteroids, and salicylic acid along with oral retinoids, methotrexate, and tumor necrosis factor inhibitors as most helpful.
  
  
  
  Pityriasis rubra pilaris remains a challenging diagnosis without established and specific treatment. Our data highlight new potential avenues for research with therapeutic perspective.
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Ross
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania2Department of Dermatology, Dermatopathology Section, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Chung
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Qiaoli
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Andrews
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Keller
authors.affiliation: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Jouni
authors.initials: J
authors.lastname: Uitto
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003879:Dermatologic Agents / Q000008:administration & dosage*; D004643:Emollients / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010916:Pityriasis Rubra Pilaris / Q000453:epidemiology* / Q000473:pathology / Q000628:therapy; D011446:Prospective Studies; D020156:Salicylic Acid / Q000008:administration & dosage; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D003879:Dermatologic Agents; D004643:Emollients; D020156:Salicylic Acid