Scratch that itch!
Or do not as the case may be. Itching is an unpleasant sensation in the skin, which makes us want to scratch, but usually only results in a worse itch. The theory is that damage to the skin causes release of proteins and chemical messengers, which act directly on the nerve endings causing an itching sensation. Scratching or rubbing the skin, relieves the itch by disturbing the rhythm of impulses in the nerves, but only affords temporary relief - as soon as the rhythm is restored, the itch returns, often with increased vengeance because of further trauma to the skin.
There are hundreds of triggers that make us itch.
I tend to think of them in terms of those that we can see - bites, rashes and eczema, and often, more serious, the ones where the only visible sign are the scratch marks we make ourselves. Generalised itching without an obvious cause should never be ignored - rarely, it could be a sign of liver disease or even lymphoma, but here are some tips on how to deal with common itches.
Hand dermatitis
A common problem, where hands become red and itchy in response to contact with chemicals like detergents, shampoos, polishes or solvents, or animal fur, particularly dogs, cats and horses. Even peeling citrus fruits can be a trigger for some. It is important to avoid the cause - wear gloves wherever possible, but be careful with rubber gloves as these can exacerbate the problem and wash hands regularly in tepid water, avoiding perfumed soaps. Always use an emollient cream after washing to keep the skin hydrated. It's important that protection is continued after the initial rash has healed as it takes some time for the skin to recover its barrier function.
Eczema
The commonest form of eczema, atopic eczema, affects as many as 1 in 5 school children and 1 in 10 adults.Classically the creases of the elbows and backs of the knees are involved. The skin looks red, dry and cracked.
The underlying problem with eczema is dryness and the mainstay of treatment is the use of emollients. I advise patients to use these as a moisturiser and a soap substitute as soaps tend to dry the skin making the condition worse. Flare ups need steroid creams but only use these as prescribed and occasionally antibiotics are needed for secondary skin infections. On a practical note, keep your nails cut short to minimise skin damage from scratching. For more information look on the National Eczema Society website on www.eczema.org
Bites and stings
We are all familiar with the raised red bumps that itch intensely and ruin many a holiday. The itching is caused by release of histamines in the skin. Prevention is better than cure here - cover up, particularly at dusk when bites are most common and use a good quality insect repellent especially around the ankles.
Creams containing antihistamines are available from chemists but are only marginally effective and hydrocortisone cream, also available over the counter, may give more relief. Antihistamine tablets help reduce the itch but can cause drowsiness, in which case they are best taken at night. Some people develop severe allergic reactions to wasp or bee stings called anaphylaxis, where the lips, tongue and airways swell causing difficulty breathing. This is life threatening and is a medical emergency requiring immediate medical care.
Nettle rash
Nettle rash (or urticaria) is an allergic reaction to anything from soap powders to something in our diet, commonly seafood, nuts and summer fruits. The raised wheals are caused by histamine release and treatment involves avoiding the triggers and antihistamines. The problem with allergic reactions is that they can become more severe with repeated exposure and in extreme cases steroids and even adrenalin need to be used. And contrary to popular belief, you can suddenly become allergic to something you have been exposed to several times before.
Prickly heat
1 in 10 people in the UK suffer from the pink spots and blisters that occur on sun exposed skin. Typically the rash occurs on day three of a sunshine holiday and once formed the itching lasts for days spoiling that long awaited break. Contrary to popular belief, most cases have little or nothing to do with heat or sweating but are due to sensitivity to the UVA portion of sunlight. If you are a sufferer, avoid the sun between 11am and 3pm when UVA concentrations are greatest and invest in a high SPF sunscreen with a 4* rating (it's the star rating that gives the UVA protection). UVA screens tend to degrade quickly so you will need to reapply the cream regularly. Remember that UVA can penetrate clouds, water, glass and even light clothing. Taking a daily 15mg betacarotene supplement, starting a week before departure can help.
Once the rash has developed, antihistamines may help, but beware - they can cause photosensitivity in some individuals making matters worse. Calomine lotion offers temporary relief but is often ineffective and many people find a steroid cream more useful.
Scabies
Believe me the nicest people can get scabies, which is due to infestation by the skin mite sarcoptes scabiei. It's our own allergic reaction to the mite, not the mite itself that causes the intense itching, which is why symptoms can develop as long as 6 weeks after initial infestation and may persist after treatment. The commonest sites to see the itchy papules and burrows are between the fingers and on the wrist. The mites only survive 36 hours off the skin so transmission from infected bedding is not as common as you think. There are several lotions available over the counter to treat scabies. Remember, you usually need two treatments a week apart and avoid applying after a hot bath as this can increase absorption into the bloodstream taking it away form where it needs to work.
Thrush
Vaginal thrush is common and most women will suffer the symptoms of vaginal itching and redness caused by the yeast candida albicans. In fact 1 in 5 women have evidence of this fungus living in the vagina without any symptoms at all. Most of the time the acidic environment in the vagina and the normal bacteria that live there keep candida under control, but there are lots of different factors that can upset that delicate environment and allow thrush to flourish - antibiotic or steroid treatment, diabetes, pregnancy and stress to name a few. If you are a sufferer, avoid any perfumed soaps or bubble baths as these alter the pH in the vagina, only wear loose fitting cotton underwear and avoid tight jeans. Candida is often carried in the digestive system so wipe from front to back when going to the toilet to avoid sweeping the infection from the bowel to the vagina. A first attack should always be confirmed by your doctor but if you have had it before and recognise the symptoms then creams and pessaries or tablets taken by mouth can all be bought from the chemist.
Pruritus ani
This is a common and troublesome condition characterised by intense itching around the anus. Often no specific cause is found. It can be associated with anxiety or depression but to be fair the condition can cause so much distress that depression results and it's often difficult to distinguish between chicken and egg. Sufferers tend to wash obsessively and aggressively which can make things worse, so try to wash gently and just once daily. Avoid harsh toilet paper, particularly if its coloured - cheap dyes can exacerbate the irritation. In fact ideally, olive oil and cotton wool should be used instead wherever practical. Steroid ointments help reduce the inflammation and creams containing zinc are effective as a barrier to any faecal soiling which makes the itching worse. In extreme cases local anaesthetic creams have been tried but, although they help some people, good evidence for their use is lacking.
