What Is Itching?
Pruritus (itching) is the predominant symptom of inflammatory skin disease. It lacks a precise definition and can best be defined indirectly as a sensation that leads to a desire to scratch.
What Are the Causes of Itching?
Itching can occur as a symptom of many health conditions. The common causes are,
1) Allergic reactions to foods, insect bites, and pollen.
2) Skin conditions such as eczema, psoriasis, dry skin, pediculosis corporis, scabies, onchocerciasis, ascariasis, and ancylostomiasis,
3) Use of irritating chemicals, cosmetics, and other substances.
4) Intake of drugs like Aspirin, Polymyxin, Morphine, Codeine, Scopolamine, and D-tubocurarine.
5) Malignancies such as lymphoma, leukemia, multiple myeloma, and other rare cancer types,
6) Metabolic and endocrine conditions such as hyperthyroidism, hypothyroidism, diabetes mellitus, chronic renal failure, and obstructive biliary disease.
7) During pregnancy, itching can occur with a skin rash causing pruritic urticarial papules and plaques of pregnancy (PUPP).
8) Psychogenic pruritus, in this condition, a patient may have a false belief of parasitic infestation.
9) Hematologic disorders such as polycythemia vera, paraproteinemia, and iron deficiency anemia.
What Are the Types of Itching?
Itching can present as,
1) Tickle sensation, which is more akin to touch. It often occurs due to mild stimulation moving across the skin and remains associated with behaviors such as smiling, twitching, and goosebumps. This sensation is very transient and quickly relieved.
2) Physiological itch is a short-lived cutaneous response of sufficient intensity to provoke scratching, but it does not result in significant skin irritation.
3) Pathological itch occurs in various primary or secondary skin disorders and several systemic disorders resulting in intense cutaneous discomfort.
4) Alloknesis is an abnormal sensory state in which stimuli that do not cause itching (such as a light touch of clothing) can cause itching.
What Are the Symptoms of Itchy Skin?
Itchy skin can affect small areas, such as the scalp, an arm or leg, or the whole body. It can also occur without any noticeable changes on the skin. Itchy skin may also occur associated with,
Spots or blisters.
Leathery or scaly patches.
As you rub or scratch the skin, it gets itchier. The more it itches, the more you scratch. Breaking this itch-scratch cycle can be difficult. Sometimes, itchiness can last for a longer time.
How to Diagnose the Cause Behind Itching?
The doctor might do a physical examination and ask questions regarding medical history. When the doctor thinks that itchy skin occurs due to a medical condition, the doctor may recommend basic diagnostic tests to rule out the cause. The diagnostic tests recommended are,
1) Blood Tests:
A complete blood count can provide evidence of an internal condition causing itching.
2) Tests of Thyroid, Liver, and Kidney Function:
Liver or kidney disorders and thyroid abnormalities may also cause itching.
3) Chest X-Rays:
A chest X-ray can show enlarged lymph nodes occurring due to itchy skin.
4) Skin Test:
It helps to determine the allergic reaction to other substances.
How to Treat Itching?
Most cases of itching are not severe. To feel better, you can follow some simple steps such as,
1) Applying cold compresses.
2) Using moisturizing lotions.
3) Taking lukewarm or oatmeal baths.
4) Using over-the-counter hydrocortisone creams.
5) Avoid scratching of skin and excess exposure to high heat and humidity.
The other essential step to managing pruritus is identifying and treating the fundamental cause, either dermatological or systemic. Other helpful measures to get rid of itching are as follows.
Clothes and environment: Pruritus is temperature-dependent. Wearing light clothes, maintaining cool room temperature, using light bedclothes, and a cool shower before sleep can alleviate pruritus.
Emollients: Pruritus due to dry skin, especially in the elderly, can be relieved by the use of emollients like soft paraffin, moisturizing cream, oils, etc.
Antipruritics: There is no available effective and specific antipruritic drug. The role of sedative antihistamines to reduce itching in atopic skin is controversial.
Topical antihistamines and corticosteroids should not be used in the absence of visible signs of inflammation.
Topical Capsaicin has been found effective in limited disease.
Tricyclic antidepressants may be helpful in some, especially emotionally distressed patients.
Topical Menthol and Crotamiton have also been used with variables.
Opioid receptor antagonists like Naloxone have shown some promise.
Specific therapies like parathyroidectomy, ultraviolet B (UVB) for chronic renal failure, and cholestyramine and UVB for pruritus secondary to liver disease have been found useful.
When Itching Needs a Doctor’s Consultation?
A doctor's consultation is needed when the itching,
1) Lasts more than two weeks and does not improve with self-care measures,
2) Remains severe, causing a disturbance in the daily routine,
3) Comes suddenly and frequently without any apparent cause,
4) Affects the whole body,
5) Accompanied by other signs and symptoms such as weight loss, fever, or night sweats.
If the itching persists for three months despite treatment, see a dermatologist to know the underlying cause and to rule out other conditions.
What Are the Complications Faced Due to Itching?
Itchy skin lasting for more than six weeks can affect the quality of life. It may disturb your sleep or cause anxiety and depression. Prolonged itching and scratching can increase the intensity of the itch, possibly leading to skin injury, infection, and scarring.
If you have any diseases that cause itching, treating the condition may help. You may need other treatments according to the causative agents. Contact your healthcare provider if the itching remains severe with no apparent cause and does not disappear after a few weeks.
Frequently Asked Questions