Anal dermatitis cumulative toxic L24.9

• The most frequent cause is a disturbance of the fine continence of the anorectal continence organ (sphincter insufficiency), caused by internal haemorrhoids, anal prolapse or mariscs.
• Acute anal eczema is usually caused by exogenous irritation (lack of hygiene, sweating, diarrhoea, mechanical irritation e.g. after marches or endurance runs; use of rough, coarse toilet paper).
• Chronic (non-atopic, non-contact allergic) irritant toxic anal eczema is usually the result of continuous secretion from the anal canal. Less frequently it is caused by irritant substances such as disinfectants.
• Irritant toxic mechanisms include: chronic, inflammatory or tumorous intestinal diseases with secretion flow from the anus, chronic diarrhoea, incontinence, fistulas, prolapse, inadequate anal hygiene, anatomical abnormalities (funnel anus), parasitoses (oxyurs), laxative and antibiotic abuse. The resulting changes in the anal and perianal environment (pH shift, constant moisture; maceration) lead to bacterial and mycotic superposition and chronic dermatitis.

Preferred >50 years, no gender preference

• Acute anal dermatitis: Sharply defined, erosive and weeping skin areas, usually large, bright red, itchy or painful.
• Chronic anal dermatitis: "Symptom of the moist and itchy anus". Usually sharply defined, weeping erythema of the anal and perianal region with crumbly scaling as well as punctiform and extensive erosions, rhagades, linear scratch marks as an expression of the usually severe, unbearable itching.

(circumscriptes) atopic dermatitis; psoriasis inversa; Paget's disease extramammary; Bowen's disease; chronic candidiasis; eczema, contact dermatitis; streptococcal dermatitis, perianal

Chronic toxic anal dermatitis (anal eczema) is often complicated by a contact allergy. In this respect, it is always important to exclude a contact allergy.

• It is important to clarify and treat any underlying haemorrhoidal disease.
• In the long term, a local therapy with low-sensitizing, antiphlogistic external agents (e.g. 1-5% ichthyol) in non-irritating bases should be sought.

• Notice! The following applies to the base: Galenically simple, allergologically indifferent bases (no W/O emulsions! No creams! No carriers containing polyglycol! Frequent burning on wetting surfaces).

• Supplementary sitz baths with synthetic tanning agents (e.g. Tannolact), soap-free "anal showers".
• For acute, weeping anal eczema: application of non-irritating topical glucocorticoids (e.g. 0.1% triamcinolone acetonide in Vaseline); cleansing with olive oil; soap-free anal showers, sitz baths with synthetic tanning agents (e.g. Tannosynt liquid, Tannolact).
• In case of chronic anal eczema (irritative-toxic): treatment and elimination of the underlying condition, e.g. haemorrhoidal disease, diarrhoea, mariscas, worm disease (tesa film tearing).
• Insertion of linen strips or gauze strips to prevent maceration.
• In the case of chronic anal eczema, suitable bases are exteriors that are as allergologically indifferent as possible, such as Vaselinum alb. or Ungt. molle for wool wax tolerance; also linola fat and e.g. Excipial Almond Oil Ointment. Temporary local measures with low-potency glucocorticoids such as hydrocortisone 0.5-1% (e.g. hydrogals, R120 ) are useful.

• Caution! Patients are often pre-treated with corticoid externa for a long time!

1. Proske S et al (2004) Anal eczema and its benign simulators. dermatologist 55: 259-264

2. Rajalakshmi R et al (2011) Lichen simplex chronicus of anogenital region: a clinico-etiological study. Indian J Dermatol Venereol Leprol 77:28-36

3. White hair E (2015) Genitoanal pruritus. dermatologist 66:53-59