Anus Itching (Pruritus Ani): Causes

Pathogenesis (development of disease)

Pruritus ani is usually pruritus cum materia (itching with visible skin lesions), that is, as a result of a dermatologic disease. In most cases, it is a cumulative toxic eczema. Trigger factors are proctological and gastroenterological diseases or influencing factors. Feces (stool) on the skin also causes irritation and thus can lead to pruritus ani.

Etiology (causes)

Behavioral causes

  • Diet
    • Hot spices
  • Lack of anal hygiene or excessive anal hygiene.
  • Chemical irritation by spicy meal, lubricants, soaps, etc.
  • Perineal piercing

Disease-related causes

Blood, blood-forming organs – immune system (D50-D90).

Endocrine, nutritional and metabolic diseases (E00-E90).

  • Diabetes mellitus (diabetes).
  • Food intolerances

Skin and subcutaneous (L00-L99)

  • Allergic contact dermatitis (contact allergy) – due toe.g. dyes on printed toilet paper, wet wipes with fragrances and preservatives, soaps, etc.; common contact allergens are benzocaine, cinchocaine, lidocaine or fragrances as often found in wet toilet paper, skin care or disinfectants
  • Decubitus – refers to an ulcer (ulcer) of the skin or mucous membrane, which is caused by prolonged exposure to pressure (eg, wheelchair users).
  • Epidermal cyst – bulging elastic node, which is filled with horny masses.
  • Hidradenitis (inflammation of apocrine sweat glands) – especially in the pubic area and armpit.
  • Idiopathic pruritus ani (with unknown cause).
  • Lichen sclerosus et atrophicus – rare, chronic inflammatory progressive connective tissue disease that is probably one of the autoimmune diseases; 4% of women with lichen sclerosus develop vulvar carcinoma (vulvar cancer; cancer of the female external genital organs)
  • Psoriasis (psoriasis)
  • Psoriasis inversa, a form of psoriasis vulgaris
  • Sinus pilonidalis (coccygeal fistula; inflammatory fistulas that almost always occur above the rima ani (gluteal fold); attributed to the ingrowth of broken hairs into the skin).

Infectious and parasitic diseases (A00-B99).

  • Chlamydial infection – most common bacterial agent of urogenital infections (infectious diseases affecting the urinary tract and/or reproductive organs).
  • Gonorrhea (gonorrhea; venereal disease).
  • Herpes simplex viruses HSV-1/-2
  • Mycoses (fungal diseases) – especially dermatophytoses (Candia albicans); especially common in diabetics and after systemic therapy with antibiotics or steroids.
  • Nematodes (threadworms)
  • Perianal streptococcal infections/streptococcal dermatitis (in children).
  • Perianal warts (condylomata acuminata; synonyms: genital warts, wet warts and genital warts) caused by HPV viruses (HPV 6 and 11).
  • Syphilis (lues; venereal disease).
  • Tinea analis – dermatophyte infection, mostly Trichophyton rubrum is involved.
  • Worm infestation (oxyuriasis); mostly to diagnose in children.

Mouth, esophagus (esophagus), stomach, and intestines (K00-K67; K90-K93).

  • Anal fissure – painful tearing of the mucous membrane at the anus.
  • Anal fistula
  • Anal marisques – sagging skin folds (marisques) around the external anus.
  • Diarrhea (diarrhea), chronic or recurrent.
  • Hemorrhoids
  • Crohn’s disease – chronic inflammatory bowel disease; it usually progresses in episodes and can affect the entire digestive tract; characteristic is the segmental affection of the intestinal mucosa (intestinal mucosa), that is, several intestinal segments may be affected, which are separated by healthy sections; possibly anal or perianal fistulas.
  • Perianal abscess – encapsulated collection of pus, which is located in the area of the anus.
  • Psychogenic pruritus ani (eg, due toanxiety, depression, stress).
  • Rectal prolapse (rectal prolapse).
  • Rectovaginal fistula – pathological connecting duct between the rectum and vagina.

Neoplasms – tumor diseases (C00-D48)

Symptoms and abnormal clinical and laboratory findings not elsewhere classified (R00-R99).

  • Fecal incontinence – inability to retain bowel movements.

Injuries, poisonings, and other consequences of external causes (S00-T98).

  • Trauma (injury) from foreign bodies, sexual practices, etc.
  • Perianal hematoma – bruise around the anus.

Medication

  • Drug intolerances