Anal dermatitis (overview)L30.8

• Cumulative toxic anal dermatitis (anal eczema)
• Contact allergic anal dermatitis (anal eczema)
• Atopic anal dermatitis (anal eczema).

Apocrine and eccrine sweat glands in the intertriginous space of the perianal region lead to a humid environment that offers an ideal terrain for irritant toxic, constitutional and contact allergic disease triggers. Aggravating factors are secretion outflows in proctological diseases, anatomical peculiarities such as funnel anus or formation of mariscs. The consequences are macerations and epithelial exfoliation. In this respect, the picture of anal eczema, regardless of its cause, is often that of a (uniform) erosive-weeping, usually torturous-itching dermatitis. In case of sensitization to local therapeutics, all kinds of care products, see below contact allergic anal dermatitis (anal eczema).

In the causal clarification of allergic contact eczema, a search must be made for potential allergens in basics, preservatives or active ingredients in external preparations (ointments, suppositories). Intimate sprays, powders, condoms, dyed toilet paper, detergents and disinfectants can also cause contact sensitization. It is important to exclude hemorrhoidal disease, inverse psoriasis and atopic diathesis (see differential diagnosis below).

• Frequently:
• inverse psoriasis or intertriginosa psoriasis
• Streptococcal dermatitis, perianal
• Perianal candidiasis
• perianal tinea
• Erythrasma
• lichen sclerosus et atrophicus
• lichen planus
• lichen simplex chronicus
• Oxyuriasis.
• Rarely:
• Pemphigus chronicus benignus familiaris
• pemphigus vegetans
• Dyskeratosis follicularis (M. Darier).
• Bowen, M.
• Paget, M., extramammary
• Acrodermatitis enteropathica.

• Rehabilitation of the proctological basic or concomitant disease. Avoidance of irritants and potential allergens. Soap-free cleaning of the anus with clear water. Application of local anti-inflammatory agents on the basis of lotions and pastes containing zinc.
• In case of weeping anal eczema, short-term use of ointments containing hydrocortisone(Vaseline has proven to be a good basis, as it has only a low irritant potential). A steroid-free alternative would be Lotio alba.
• If necessary, sitz baths with synthetic tanning agents (e.g. Tannosynt and Tannolact) or with disinfectants (e.g. potassium permanganate: dissolve a few crystals in lukewarm water to produce a strong pink-coloured solution).

• From a dietary point of view, it is recommended to avoid alcohol and spicy foods.
• Washing with soap should be avoided.
• The cleaning of the perianal area can be done with clear water (best bidet use-if bidet is not available, a good option would be the HappyPo Easy-Bidet (mobile hand-bottom shower) or with vegetable oils (e.g. olive oil) applied with soft paper towels.

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