Itching, burning, rash

(Contribution in progress...)

Symptoms in the area of the outer skin around the anus (anus) are among the most common reasons why patients consult a proctologist. Although usually harmless, these complaints can significantly affect the quality of life.

The most important point for successful treatment is whether a cause can be found in the rectum. The examination therefore always includes a reflection of the rectum (proctoscopy, rectoscopy if necessary).

In doing so, one looks for inflammation of the mucous membrane(proctitis), a possible fistula opening as well as an internal or external prolapse of haemorrhoids or intestinal wall. These diseases cause chronic irritation of the surrounding skin due to moisture leakage.

If the rectal examination is unremarkable, one must assume a primary disease of the skin. A possible history of neurodermatitis, allergies or psoriasis supports this assumption. In this case, referral to a specialist in skin diseases (dermatology) is recommended.

Itching, scratching, burning at the anus
When the toilet paper feels like barbed wire....

When it itches and burns

Anal eczema: forms and causes

Irritative-toxic anal eczema

This complicated term refers to irritation of the skin caused by external influences such as moisture or irritating substances. However, these can also have an internal cause, such as anal dampness in haemorrhoidal disease or digestive enzymes in LARS (syndrome after deep rectal resection for rectal cancer). Therefore, the examination of the skin around the anus (perianal) always includes an examination of the rectum. Treatment depends on the cause, for example, haemorrhoid sclerotherapy can remove the dampness and the skin can recover.

Allergic Anal eczema

Allergic anal eczema belongs to the group of contact dermatitis, which is triggered by local exposure to an allergic substance (allergen). It is a reaction mediated by immune cells (T-lymphocytes). It is therefore understandable that this process of cells migrating into the affected area takes some time (late-type allergy) and leads to an initial thickening or swelling of the affected skin area, accompanied by redness.

In the area of the anus, common contact allergens are found in the preservatives and fragrances of moist toilet paper, personal care products (wool wax and wool wax alcohols in creams) and washing lotions.

Among the drugs or active substances used on the anus, it is often the local anaesthetic components in ointments for pain.

Therefore, the first immediate measure is to leave out everything that is not absolutely necessary. An allergy test at the dermatologist is recommended to further narrow down the trigger. In severe cases, treatment with a cortisone cream is also necessary.

Atopic Anal eczema

Atopic anal eczema is also the result of an excessive immune reaction. A history of neurodermatitis in childhood or multiple allergies, a so-called atopic disposition, is often found. Typically, the clinical picture is varied, with redness, sores (erosions) and traces of nocturnal scratching. In the acute situation, usually only a cream containing cortisone helps. However, cortisone preparations are only "allowed" on the anus for intervals of up to about 7 days, as longer-term use can cause permanent damage to the skin. This "thinning" of the skin is called atrophy. Alternative substances are therefore used as long-term treatment, such as the immunomodulators Protopic® and Elidel®.

A common disease that is often not recognised

Anal psoriasis (psoriasis)

Psoriasis is a common chronic inflammatory disease caused by an overreaction of the immune system (autoimmune disease), not only of the skin. In Germany, approximately 1,500,000 people (2.2%) of adults are affected to varying degrees. The disease can occur at any age, but mostly before the age of 40. A special feature of anal psoriasis is that it can also occur independently of skin changes on the rest of the body and often does not have the typical clinical picture of psoriasis.

A rhombic reddening (erythema) surrounding the anus is visible. Typical are tears (rhagades) that look like they have been scratched with a razor blade, which can extend from the anus to the periphery in a star shape or only occur in the midline. Itching is possible, but not always present. Traces of blood on the toilet paper are often noticed. 

Due to the particularities of the anal region (contact of the buttocks, "occlusive situation"), the typical signs that psoriasis shows on other body regions, such as skin thickening (plaques) and scales, are often missing.

In the acute stage, ointments containing cortisone are the best remedy; in the chronic stage, active substances similar to vitamin D can alleviate the symptoms (Silkis ®, Daivonex ®).

Often misdiagnosed as haemorrhoidal disease - anal psoriasis
Anal psoriasis with typical redness and rhagades (see text)

"Could that be a fungus ...?"

Infectious Skin diseases

Skin diseases caused by infectious pathogens are much rarer than expected.

Fungal diseases: Candida and dermatophytes

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Viral diseases: Genital warts (Condylomata accuminata)

Bacterial infections: Streptogenic dermatitis, erythrasma

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Viral diseases: Herpes simplex

Occurrence (epidemiology)

Human herpes viruses 1 and 2 (HHV-1 and HHV-2), often abbreviated to HSV-1 and HSV-2, are the main viruses found in humans. HSV-1 is predominantly transmitted through everyday contacts and causes cold sores, HSV-2 is one of the predominantly sexually transmitted diseases and is responsible for genital and anal herpes. These strict boundaries have shifted somewhat in recent decades, so that HSV-1 is also found in the intimate area and HSV-2 on the lips and mouth. Recent studies show that herpes viruses can survive in moist environments for longer than previously assumed, up to several weeks, so that direct transmission from person to person is not necessarily present in every case.

In representative samples from the population, specific antibodies against HSV-1 can be detected in 67 % of those examined and against HSV-2 in 17 %. Current studies from the USA show continuously declining numbers over the last two decades, with a slight increase in HSV-1 infections in the genital and anal areas. HSV-2 infections are of additional importance, as they probably favour the transmission of the HIV (AIDS) virus.

Clinical picture in herpes simplex

The typical clinical picture of a herpes infection is the appearance of vesicles in groups, often in different stages of development of fresh and already scabbed vesicles next to each other.

Patients often complain of severe, burning pain during the initial infection and also general symptoms such as fatigue and fever.

The viruses have the property of attaching themselves to the spinal ganglia via the peripheral nerves and causing symptoms again in the supply area of the respective nerve during phases of reduced immune defence (e.g. febrile infections, pregnancy, sun exposure). These episodes are often preceded by non-specific symptoms - "tingling", characteristic itching - for a few days.

In the florid stage, herpes simplex can usually be recognised at first glance. A diagnosis can be confirmed by PCR smear.

Herpes simplex infection anal
Typical with HSV-1: grouped blisters on the lip

Herpes simplex: prevention and treatment

Prevention is difficult because, in the case of HSV-1, infection often occurs in childhood before appropriate awareness of the problem can be achieved, and in the case of HSV-2, because the manifestations in the genital area are not always perceptible to the person affected.

The potential carrier is best able to protect his environment by avoiding contact during the symptomatic phase and by practising careful hand hygiene. Condoms protect to a certain extent, although not completely.

It is particularly important to avoid infecting the newborn at birth. These neonatal infections can also be severe and sometimes even fatal, especially if the mother became infected late in pregnancy and has not yet formed protective antibodies.

There are now a number of medicines available as creams and tablets (aciclovir and related substances) that can mitigate severe infections and shorten the duration of relapses. They probably cannot prevent chronification. Tolerability is generally very good.

Vaccines are being developed, but no commercially available vaccine was available by the end of 2021.

And finally, a look at the medical literature again

Skin diseases: Bibliography

Armstrong, G., Schillinger, J., Markowitz, L., Nahmias, A., Johnson, R., McQuillan, G., & Louis, M. (2001). Incidence of herpes simplex virus type 2 infection in the United States. American Journal of Epidemiology, 153(9), 912-920.

Chemaitelly, H., Nagelkerke, N., Omori, R., & Abu-Raddad, L. (2019). Characterizing herpes simplex virus type 1 and type 2 seroprevalence declines and epidemiological association in the United States. PLoS ONE, 14(6),

Dayaram, A., Franz, M., Schattschneider, A., Damiani, A., Bischofberger, S., Osterrieder, N., & Greenwood, A. (2017). Long term stability and infectivity of herpesviruses in water. Scientific Reports, 7(1), 1-10.

Kriebs, J. (2008). Understanding Herpes Simplex Virus: Transmission, Diagnosis, and Considerations in Pregnancy Management. Journal of Midwifery & Women's Health, 53(3).

Xu, F., Sternberg, M., Kottiri, B., McQuillan, G., Lee, F., Nahmias, A., Berman, S., & Markowitz, L. (2006). Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States. JAMA, 296(8), 964-973.

DR. BERNHARD HOFER & COLLEAGUES

Specialists in surgery, proctology

Brienner Str. 13, D-80333 Munich, Germany

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