How to take the sting out of horrid rashes
LIVID HIVES THAT FLARE UP FOR NO REASON
RED spots or itchy raised white or pink weals, similar to nettle rash, appearing over large areas of the body could be hives.
Hives, also known as urticaria, is very common — one in five people will get it, though it is more common in adults than children.
While the cause is an excess of histamine released by cells in the skin, it is not clear what triggers this chemical release.
Histamine is usually unleashed by the body to provoke itching, sneezing and other responses in reaction to an invasion by a foreign substance, such as pollen.
‘Of course, patients want to know what has triggered hives and what they can do to prevent it coming on again, but a lot of the time we can’t actually find a cause,’ says Juber Hafiji, a consultant dermatologist and spokesman for the British Skin Foundation.
This is idiopathic, or unexplained, spontaneous urticaria, which generally comes and goes within 72 hours — but it can be three days of hell.
‘Patients are otherwise fit and well, and for no rhyme or reason their immune system has been activated, causing them this itchy, unsightly misery,’ says Dr Hafiji.
This can be a one-off, or patients may have recurring bouts of urticaria that fizzle out after a short time. But some suffer chronic urticaria, which can remain or come and go for weeks or even years. In either case, the rash can range from very small red spots, barely a few millimetres across, to patches the size of a hand or more, appearing anywhere over the body.
Triggers are sometimes identified and can range from a common cold and contact with an animal to sunlight or certain foods — shellfish, nuts, apples and peaches are common culprits — and medicines. Bee and wasp stings can also spark the condition. Generally, though, allergy is not a common cause of urticaria, according to the British Association of Dermatologists.
Common cardiac and blood pressure drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), given to relieve pain and reduce inflammation, can aggravate urticaria, as can antibiotics.
There are, says Dr Hafiji, many rare types of urticaria with known causes, reflected in their names — including solar, cold and aquagenic (water-triggered) urticaria.
‘I saw a patient a few weeks ago who only gets urticaria when he exercises. Another only gets it when he gets into a freezer van, which he has to do daily as part of his job.’
As with many skin conditions, urticaria can be treated but not cured. Antihistamine tablets, available over the counter, can reduce the rash and itching, but won’t work for everyone.
In severe cases a GP or specialist might prescribe a drug such as ciclosporine, which works by suppressing the immune system.
A new drug called omalizumab has recently been approved for use in people suffering from chronic spontaneous urticaria (if welts appear for longer than six weeks or recur many times over a long period of time).
This is a ‘biologic’ drug, so-called because it mimics natural molecules in the body, unlike medicines that are chemically synthesised. It works by blocking specific antibodies that would otherwise trigger allergic reactions.
Omalizumab is injected into the thigh or buttocks once every four weeks for up to six months. It is given in hospital outpatient clinics, where patients are monitored for an hour or more in case there is an allergic reaction.
Clinical trials found half the participants noticed a good improvement or complete resolution of symptoms after three months of injections. As a short, sharp fix, steroid tablets ‘can be very handy to help that person who is getting married or going on holiday to control their symptoms in an acute situation’, says Dr Hafiji.
‘But all steroids have long-term consequences in terms of weight gain, raised risk of diabetes and cataracts and stomach ulcers, to name a few,’ he adds, ‘so for the minority of patients who have chronic, long-term urticaria you need other solutions.’
In about 10 per cent of cases, hives is associated with angioedema, a swelling beneath the skin’s surface. This is not itchy, but can be painful.
It can affect the hands, feet, skin around the eyes and genitals, but can also cause swelling in the lips and on the tongue and throat. ‘This has greater ramifications in terms of breathing difficulties’, says Dr Hafiji, but is very unlikely to cause serious problems.
But take no chances. Rapid swelling, combined with difficulty breathing and swallowing and a raised heart rate might not be hives but the onset of anaphylactic shock, a severe reaction to an allergy — call 999 immediately.
BLISTERS THAT SPREAD RAPIDLY
SORES and blisters that turn into oozing patches and scabs could be impetigo. Caused by the bacterium
Staphylococcus aureus, impetigo is the most common skin infection suffered by children, but can affect people of all ages.
The germ thrives in humid conditions, and while it can invade ‘normal’ skin, it is quick to exploit broken skin damaged by cuts, head lice, scabies, cold sores or eczema. ‘We see a lot of this,’ says Dr Hafiji. ‘Adults can get it but it’s usually children, because the skin barrier needs to be breached and, of course, they’re always falling over.’
The condition can spread rapidly through families and school classes ‘by skin-to-skin contact or, less often, by bedding, clothing and towels’, according to the British Skin Foundation.
However, impetigo can also arrive out of the blue, with no hint of where it came from.
In rare cases, says Dr Hafiji, people taking immunosuppressant drugs, perhaps to prevent transplant rejection or treat other skin problems, may contract impetigo even with an intact skin barrier because their immunity is compromised.
Children with impetigo should be kept off school until scabs have fallen off — usually a week after the start of treatment — and hands washed immediately after touching infected skin patches.
Always get a proper diagnosis from a doctor — in very rare cases what appears to be a simple dose of impetigo can mask cellulitis, a serious infection of the deeper layers of the skin which will respond to antibiotics but, if left untreated, can be life-threatening.
Sore, itchy and unsightly while it lasts, without treatment it will clear up in about two to three weeks, leaving no scars. With treatment, however, the bug and all signs of it can be eradicated in about half that time.
Antibacterial soap and water should be used to gently remove any crusting that has formed, then over-the-counter antibiotic creams or ointments containing mupirocin or fusidic acid are rubbed on and around the patches two or three times a day.
If the condition is widespread, slow to respond or keeps coming back, oral antibiotic tablets such as flucloxacillin, erythromycin and cephalexin may be prescribed by a GP at the same time.