What is Itching?
Itching (pruritus) is the sensation you feel in your skin that makes you want to scratch. It can be localized to a particular area or all over the body.
The impulsive need to scratch can be overwhelming, however it could cause harm by breaking the skin and instigating infection.
Whilst the occasional itch is annoying and inconvenient, constant itching can be a sign of something more serious. (1)
Causes
There are many possible causes for itching, some might be obvious, particularly if accompanied by a skin rash. Others may be as a result of an underlying medical condition. We will detail some of the more common possible causes.
Dry Skin
There are many reasons why our skin can become dry. These include spending too long in air-conditioned or centrally heated environments and showering or bathing too often.
However, aging is the most common cause of itchiness in dry skin. Years of exposure to environmental factors along with less ability to retain moisture and regenerate new skin cells means dryness.
Medically referred to as xerosis, this itch can be occasional or persistent and affecting someone’s quality of life. (2)
Dermatitis
There are two types of dermatitis, those caused by contact irritants and those that are longer lasting skin conditions.
Contact dermatitis happens when our skin comes into contact with something that causes a rash. It could be something as simple as soap or a piece of jewellery containing nickel. Maybe your hands spend a lot of time in water at work or you have to wear latex gloves.
The first signs may be dry, cracked hands, worsening to stinging, burning and itching. (3)
Eczema is the more common name for long lasting or atopic dermatitis. This disease is common in children but can also affect adults, although unless you had it as child this is rare. It causes dry skin that itches and can become cracked and bleed.(4)
Psoriasis
Psoriasis is long lasting skin disease develops when a faulty immune system causes skin cells to grow faster than normal. The new cells accumulate on the surface of the skin as the body is unable to shed them quickly enough.
These scaly, red, raised patches of skin tend to appear on the elbows, knees, lower back and scalp. This condition can look unsightly and itches. (5)
Allergic Reactions
When the body consumes or comes into contact with something it’s allergic to the result can be a skin rash that will itch.
There are many types of allergens from food such as nuts and shellfish to insect bites, pollen, animals and medication. (6)
Fungal Infections
About 20 percent of the general population will be affected by a fungal infection. These include things like ringworm, athletes foot and jock itch.
They manifest as red, itchy areas on the skin and are easily treated with topical medications. (7)
Viral and Bacterial Infections
Common viral illnesses can cause a red rash in the skin which will itch, such as measles and chickenpox. (8)
Bacterial infections from streptococcus, staphylococcus and salmonella can cause a red itchy rash called hives (urticaria). This condition appears as raised red lumps on the skin and may affect part or all of the body. (9)
Bugs and Mites
We have briefly mentioned allergic reaction to insect bites, but there are so many other bugs that can bite. Some can pass on disease as well as cause itchiness at the site where you are bitten.
The culprits include mosquitoes, bed bugs, mites, fleas, spiders, ticks and fire ants, to name a few. If you experience difficulty breathing, a swollen face, dizziness, vomiting or an unexplained skin rash see a doctor straight away. (10)
Head Lice
Most parents dread seeing a child scratching their head, it could be a sign they have picked up head lice. This common infestation affects between six to twelve thousand school age children every year.
Despite popular belief, head lice don’t discriminate between clean or dirty hair, they just want to feed on human blood. Passed from head to head by contact they make your scalp very itchy. (11)
Scabies
Whilst not visible to the naked eye, the mite which causes this skin infestation burrows under the skin to feed. The reaction from our body is an extremely itchy rash.
Scabies can live in bedding or clothes for about three to four days, but is usually spread by human contact. Fortunately there are medications available to treat scabies so it does not last long. (12)
Medical Conditions
ertain medical conditions and diseases have the ability to make the skin itch. These include, kidney failure, liver disease, thyroid problems, iron deficiencies, diabetes and some cancers.
It is likely that there will be no visible rash and the skin will appear normal, apart from feeling itchy. (13)
Medications
Many medications have side effects, one of these might be itchiness in the skin. If you are taking any drugs and your skin begins to irritate, check the accompanying information, it could be the cause. (14)
Pregnancy
Pregnancy can affect the skin in many ways, people may get flare ups of eczema that they have not had before. They can even find eczema which disappeared years ago reappears.
During the last few months of pregnancy hormones can affect liver function, and interfere with production and storage of bile. It can build up and enter the bloodstream causing itchiness in the skin. (15)
Symptoms
Itchy skin could be felt over localized areas or all over the body. The skin can appear normal with no visible signs of a rash or there may be redness, blisters, bumps or spots. The skin might also be dry and cracked or appear scaly or leathery in texture.
The temptation to scratch the itch can be intense, but you might find the more you scratch the more you itch. Whilst resisting this urge to scratch or rub can be difficult you don’t want to damage the skin. If you do you it will be open to infection which can cause further complications. (16)
Diagnosis
Sometimes the reason you are itching will be obvious, such as an insect bite or an allergy that you know about. You may be able to treat these conditions with the help of a pharmacist and over the counter medication.
However, there are times, especially if an itch is not going away, when you need to see a doctor.
To enable them to diagnose the cause of your itch they will take your full medical history. They will want to know how long you have experienced the itchiness and if you have any other symptoms.
It will be useful if you can pinpoint the areas that itch, they could be localized to an arm or leg. Irritation may be in your groin, armpits, elbows, behind your knees or on your head. Your whole body could be affected and the itching might be intense.
The doctor will make physical examination of the areas that concern you and listen to your chest and heart.
If the cause of the itchiness is not obvious then further tests may be needed. These include blood tests, allergy tests and tests of the area of skin affected. (17)
FAQ
What is itching? Itching (pruritus) is the sensation you feel in your skin which makes you want to scratch. It can be localized to a particular area or all over the body.
What causes itching? There are many things that can cause this irritating sensation. They include allergies, infections, insect bites, skin conditions and underlying medical issues.
How do doctors test for itching? The reason for your itch can be obvious, if not blood tests, allergy tests or skin tests might be required.
When should you go to the doctors with itching? If you have a persistent itch lasting longer than two weeks, or have symptoms which concern you, see a doctor.
Can you prevent itching? You may be aware of the cause of your itching so you can try and avoid it. To stop your skin becoming dry, stay hydrated, avoid too much air conditioning or central heating and use gentle moisturizers.
What can relieve itching? Your pharmacist can help with over the counter creams and medications that can relieve your itch. There are things like calamine lotion and menthol cream can help cool the area and make it itch less. Scratching makes you itch more, to break the cycle, maybe wear soft gloves to bed or cover the affected area. (18)
Can reducing stress help itching? Many skin disorders can be made worse by stress. Therapeutic practices like exercise, meditation, progressive relaxation, cognitive behavior therapy and music therapy can reduce stress and improve skin disorders. (19)
Can itching be treated? There many medications used to treat the causes of itching including antihistamines and corticosteroids. Your doctor will be able to prescribe what will likely work best for you after diagnosis. (20)
Summary
Itching (pruritus) is the sensation you feel in your skin which makes you want to scratch.
The impulsive need to scratch can be overwhelming but can damage the skin and lead to infection.
The many causes of itching are usually cleared up with treatment from a pharmacist or doctor. However if you experience other symptoms like shortness of breath or swelling in the facial area, seek immediate medical help.
The itch/scratch cycle is a hard one to break, therefore the sooner treatment is started the quicker your symptoms will be relieved.