Introduction
Pruritis Ani is “itchy anus”, and is a common presenting complaint to general practice. Symptoms are typically worse at night, and can keep the patient awake, and may be exacerbated by hot weather or exercise.
There can be many causes; in children threadworm is a common cause, whilst more benign causes are common in adult males. Seborrhoeic dermatitis (the same condition that causes dandruff on the scalp) is often associated with pruritus ani.
Mose cases do not have an easily identified cause, and may resolve with reassurance, and modification of hygiene practises.
Causes
- Psychological factors
- Stress and anxiety
- Excessive sweating
- +/- associated with exercise
- +/- associated with tight fitting clothing
- Over-zealous hygiene – may be associated with too much washing!
- In some – may be associated with not enough washing – especially after exercise
- Infectious
- Threadworm
- Infectious causes of diarrhoea (causing excoriation)
- Generalised skin conditions
- Seborrhoeic dermatitis
- Lichen sclerosus
- Eczema
- Candidiasis
- Psoriasis
- Local skin causes:
- Haemorrhoids
- Anal fissure
- Contact dermatitis
- Diabetes
Diagnosis
Typically clinical diagnosis assisted by history and examination. Consider also:
- Urinalysis (for glycosuria and diabetes)
- Skin scraping – for fungal causes
- Stool examination for intestinal parasites
Management
- Treat the cause!
- General hygiene advice:
- Avoid the use of soap
- Try aqueous cream instead
- Shower as soon as possible after exercise
- Avoid tight fitting clothing
- Avoid excessive scratching
- Avoid perfumed soaps and powders
- In obesity with excessive sweating, consider strapping the buttocks apart with adhesive tape
- Trial of steroid cream
- e.g. 1% hydrocortisone
- Trial of anti-fungal cream
- e.g. clotrimazole 1%
References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy