Itchy bottom
There are a few common causes of an itchy bottom, and we may find no cause, in which case we call it pruritus ani.
Threadworms (pinworms) are very common in children but rare in adults. This is a parasite infection causing intense itching around the anus and possibly the vagina, especially at night. You might notice tiny white worms around your child’s anus or mixed in poop.
In adults, hemorrhoids may be to blame. You may be able to feel one lump or more around the anus, and it may be painful when you go for a poop. You may get a few streaks of blood in the toilet bowl or on toilet tissue. These are common, and treatments are available.
Infections from a fungus or yeast (thrush can feel itchy and sore. The area will look pink, perhaps with tiny pink bumps and possibly flaky.
Psoriasis can look similar but will likely be more red than pink, with a clear border, and is a more likely cause if you have psoriasis on other parts of the body. Eczema may appear around the bottom, especially if you have a tendency to it or irritation from any cream or treatments you are using, such as perfumed moisturizers, steroid creams, or ointments for anal fissures.
Genital warts can appear as hard lumps around the anus and wider genital area and may be itchy. These are sexually transmitted and contagious to intimate partners.
Finally, a condition called lichen sclerosus causes the skin to tighten, which can be itchy. You might see some white streaks on the affected area, making it look shiny and taut.
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Is it contagious?
Threadworms are very contagious, passing from bottom to hands or clothes to mouth, so it's important to get prompt treatment and re-treat 2 weeks later. Follow simple hygiene: wash hands and nails regularly, keep fingernails short, and rinse the toothbrush before use. Children should wear underwear at night and wash it in the morning, and bed linen, towels, nightclothes, and soft toys should be washed on a high heat cycle after treatment.
Fungal infections can be contagious to other areas of your body, such as the rest of the genitals or other areas of the skin. If you have a fungal nail infection, it would be worth getting this treated as this can transfer to areas of the skin (and vice versa).
Any non-infectious causes would not be contagious.
Healthwords pharmacists' top tips
You should try to avoid scratching and keep fingernails short - avoid tights, synthetic materials, or other underwear that can cause sweating, and make sure you pat the area dry after bathing. Products from your pharmacy can help soothe and cool the area (such as aloe vera gel or menthol creams, ointments, or creams containing zinc oxide), emollients (medical grade moisturizers), and mild steroid creams can calm any inflammation.
If you think you or your child has threadworms, products containing mebendazole 100 mg, such as Vermox chewable tablets or liquid, are available and are licensed for use in adults and children over 2 years in combination with simple hygiene measures. A second dose to avoid re-infection should be taken after two-three weeks. It’s not recommended for pregnant or breastfeeding women or those under 6 months. You will need a prescription for this medication.
When should I see my doctor?
See your doctor for a prescription if you think your child has threadworms. You can try over-the-counter treatment for thrush or a fungal infection (they are treated with the same cream) and for hemorrhoids.
If you are unsure of the diagnosis or think this is lichen sclerosus, you should book a routine appointment with your doctor. If the itch is severe or painful, book an urgent appointment. Your doctor will ask about symptoms and examine the area. They may be able to prescribe something to resolve it or ease symptoms. If your doctor can’t see anything to indicate why you have an itch, they may consider extra tests such as a swab or blood tests.
It’s worth bearing in mind that a slight itch can become intense and all-consuming, which can develop into an itch-scratch-itch cycle that is difficult to break. See your doctor if your itch is persistent or if you notice any skin changes around the area.
Should my child stay off school with threadworms?
Children do not need to stay off school with threadworms.
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