ASCRS Ch17 — Dermatology and Pruritus Ani

Citation: Umanskiy K, Messaris E. "Dermatology and Pruritus Ani." In: Steele SR, et al. (eds.), The ASCRS Textbook of Colon and Rectal Surgery, 4th ed. Springer Nature Switzerland AG; 2022. pp. 311–322 (PDF pp. 318–329 of the combined textbook file). Source file: raw/ASCRS Textbook 4th Ed.pdf (full 1,198-page textbook; cite by page range within the single PDF). Seventh chapter of Part II ("Anorectal Disease").

Type: Specialty textbook chapter (reference/background, not primary literature).

Scope

Seventeenth chapter of the sequential full-textbook ingest (see ASCRS Ch01 - Anatomy and Embryology for the ingest's scope/plan). Covers pruritus ani as a single cohesive clinical entity (the chapter's "Dermatology" half is organized as one of several etiologic categories within the pruritus-ani differential, not a separate topic — so no split was needed, unlike Ch12/Ch13/Ch16): pathophysiology (the C-fiber-mediated "vicious cycle," histaminergic and non-histaminergic itch pathways), etiology (fecal soilage, diet/medications, dermatologic diseases, infections — fungal, bacterial, parasitic, viral, STI — systemic disease, gynecologic/psychological factors, anorectal disorders), diagnostic approach (history, physical exam, clinical staging, laboratory testing, endoscopy, biopsy), and the two-encounter treatment ladder (general hygiene/dietary principles through topical steroids, antihistamines, capsaicin, tacrolimus, and methylene blue anal tattooing as a last resort).

Key content

Filed as a single new condition page, Pruritus Ani. Cross-links added to four already-ingested anorectal-disorder pages explicitly named in the chapter's Table 17.1 differential — Anal Fissure, Hemorrhoids, Anorectal Abscess, and Anal Fistula — plus Hidradenitis Suppurativa (named as a dermatologic-disorder cause, with this chapter's brief Hurley-consistent staging summary), and lighter mentions of Crohn Disease (fecal-soilage contributor) and Anal Stenosis (existing Paget's/Bowen's mention). Also flags forward references to anal intraepithelial neoplasia and anal cancer (Bowen's disease, Paget disease, cloacogenic carcinoma, anal-margin SCC as refractory-pruritus differentials) — detailed content queued for ASCRS Ch19/Ch20.

Limitations

• Textbook chapter, not primary literature; cited trial/series data (hydrocortisone RCT, capsaicin crossover trial, tacrolimus RCTs, methylene blue tattooing studies) are the chapter authors' synthesis, not independently re-verified.
• Explicitly notes up to 25% of cases remain idiopathic despite extensive workup, and that a systematic review graded methylene blue tattooing evidence as weak due to small patient numbers.
• Anal-neoplasia-related pruritus content (Bowen's, Paget's, cloacogenic carcinoma) is mentioned only briefly as part of the refractory-pruritus differential — full disease-specific content is out of scope for this chapter and this page.

Relevance

Seventeenth entry in the ASCRS ingest. Adds one new condition page with an unusually wide (for a single-topic new chapter) cross-link fan-out, given how many already-ingested anorectal conditions this chapter's differential-diagnosis table explicitly named. Chapter 18 continues Part II with "Sexually Transmitted Infections of the Colon and Rectum."