Itchy skin or pruritus is a very common symptom that we all experience on a daily basis. It generally lasts just a few moments and goes away by itself, or it can be relieved with a gentle scratch. Scratching may be pleasurable and rewarding for some, but when itching is recurrent, lasts for longer periods of time, or spreads to a wide area it transforms to something annoying, and it may start to cause concern and worries.
Table of Contents
What is pruritus?
Pruritus is the medical term for itching and is the most common symptom in the field of dermatology. The skin has a dense network of nerve fibers connected to different types of receptors; this allows us to feel and understand the environment and what happens around us quite well: from temperature, to touch, pain, vibrations and itching. Pruritus is a complex symptom because it can be linked to a wide range of diseases and conditions, and it may have many different presentations.
Acute pruritus is defined as lasting less than 6 weeks, while chronic pruritus lasts more than 6 weeks and affects around 15% of the global population.
What causes itchy skin?
Allergens, pruritogens and irritants are substances from the environment we may come in contact with that can cause dermatological reactions and itchy skin. Dry skin, cracked skin and healing skin may also cause itching. Dermatological conditions such as eczema and psoriasis or viral, fungal, bacterial and parasitic infections cause itching as well. Pregnancy may cause itching; some medications also cause itching as side effect. In rarer and more serious cases, liver, kidney and thyroid problems or some types of cancers may also be the cause of pruritus. Moreover, itching may arise also from emotional or mental stressors and from psychiatric disorders, in which case it is called psychogenic pruritus.
To narrow down the possible cause you should answer some questions:
- Is pruritus localized or is it all over your body?
- Is it acute or is it chronic?
- Are there visible skin lesions?
For a proper and reliable diagnosis you will need to go to your GP for a consultation: family history, medical history, physical examination, and further tests may be needed to point out the exact cause and the best treatment plan.
The following are some of the possible causes based on the location or characteristics of pruritus. It is not an exhaustive list, nor it is 100% indicative as often diseases and conditions manifest themselves differently in different individuals.
Itching all over body
Allergic reactions can lead to itching all over the body, as can certain medications or liver and kidney disease. Sun tanning, especially if you haven’t used sun protection may cause generalized itching to all exposed areas. Dehydration may also cause itching all over your body.
Pruritus at night
Itching is often reported as worse during nighttime. This is because our mind has less distractions and we focus on body sensations; this may also lead to troubles falling asleep. Another reason for itching at night may have something to do with what you are wearing or to your bed linen as well as due to dust mites.
Itchy hands and feet
Dishydrosis, eczema, contact dermatitis, insect bites, skin infections, diabetic neuropathy, dry skin are some of the possible causes of itchy hands and feet.
Itchy arms and legs
Sometimes itchy arms and legs may be caused by neuropathic dysesthesia: compressed nerves in the cervical or lumbar spine due to disk herniation, osteoarthritis or other causes may lead to the sensation of pruritus in the limbs. When it happens in Summer or on sunny days, itching may be caused by a reaction to UV exposure.
Itchy anus
Anal itching may be embarrassing but it is actually a common symptom. Synthetic underwear, sweat, diarrhea, washing too little or washing too much are all possible causes. Hemorrhoids, anal fissures and STDs are other possible causes.
Itchy skin with no rash
When there is no rash, skin may be itchy due to simply being dry or dehydrated, or it may be a sign of a systemic disease such as liver and kidney problems or a lymphoproliferative disease.
Itching, medications and prescription drugs
Several classes of medications both OTC and prescription drugs may cause itching. ACE-inhibitors, a common tablet to treat hypertension, statins for high triglycerides, NSAIDs, antibiotics and opioids are some of the drugs that may cause pruritus.
Itchy skin in the elderlies
In the elderlies a common cause of pruritus is simply dry skin (xerosis). Increasing the water intake and applying a moisturizer regularly should resolve the symptom.
Itching and pregnancy
Also known as pruritus gravidarum, itchy skin during pregnancy is not uncommon. It is likely caused by cholestasis of pregnancy or by hormonal changes or by the skin in your belly that stretches causing tears. I’ll talk specifically about itching and pregnancy in a dedicated article.
Home remedies for itchy skin
Depending on the causes of your pruritus, home remedies may ease and resolve the itching, or you may need a different approach.
- Wear loose cotton clothing. Other materials may be rough or irritate the skin and clothing too tight may cause itching as well.
- Use gentle soaps and skin products.
- Keep your nails short and smooth, so that scratching won’t damage the skin.
- Use a moisturizer, to restore the skin barrier and hydrate the skin.
- Drink plenty of water to make sure you are not dehydrated.
- Use a humidifier in your house if you live in a dry environment.
- Icepacks or other cool compresses may immediately relieve itching.
- Menthol or capsaicin creams are available OTC and may provide relief as well.
If itching is persistent, generalized or spreads to other areas, if there are other symptoms or cutaneous manifestations, or if it affects your life you should talk to your family doctor or to a dermatologist: with your family and medical history and with a physical examination they will be able to make a diagnosis. Sometimes further tests such as blood tests, allergy patch test or a skin swab may be advised; more rarely a skin biopsy may be performed as well.
Treatment options will depend upon the diagnosis and may include antihistamine medication, or topical and systemic corticosteroids, opioid receptors antagonists, antidepressants, immunosuppressants.
Sources
- Fitzpatrick’s Dermatology, 9th Edition
S Kang et al – McGraw-Hill, 2019
ISBN: 978-0-07-183783-5 - Physiology and pathophysiology of itch.
F Cevikbas, EA Lerner – Physiological Reviews, Mar 2020
DOI: https://doi.org/10.1152/physrev.00017.2019 - Itchy skin
UK National Health Service, Jul 2020
https://www.nhs.uk/conditions/itchy-skin/ - Brachioradial Pruritus.
BA Robbins, GJ Schmieder – StatPearls, Sep 2020
https://www.ncbi.nlm.nih.gov/books/NBK459321/ - Pruritus Associated with Commonly Prescribed Medications in a Tertiary Care Center.
AH Huang et al – Medicines, Sep 2019
DOI: https://dx.doi.org/10.3390%2Fmedicines6030084 - American Academy of Dermatology (AAD)
https://www.aad.org/public
