What Is Pruritus (Itchy Skin)?

Overview

Pruritus, also known as itching, is a sensation on the skin that triggers the urge to scratch. It can occur due to various skin conditions, medicines and underlying medical conditions. Pruritus can affect certain or multiple areas of the body. If it persists for more than six weeks, it is considered chronic.

In this article, we will explore the common triggers, effective management strategies, and potential treatment options for pruritus, to help you better understand and address this condition.

Types of pruritus 

There are many types of pruritus classified based on the cause and origin of the itchiness on your body.^1,7

The most common types of pruritus include: 

• Brachioradial pruritus: A nerve disorder that causes itching, stinging or tingling in the upper arm
• Nocturnal pruritus: A condition that occurs when you need to itch at night. This condition is also referred to as nighttime itching
• Pruritus ani: A skin condition that causes itching in the area surrounding your anus
• Senile pruritus:¹ A chronic itching condition that typically affects people over the age of 65
• Uraemic pruritus: Also known as renal pruritus, is a persistent itching condition that can affect people with chronic kidney failure, particularly those undergoing hemodialysis 

Other types of pruritus include:  

• Cholestatic pruritus:² Occurs in people with impaired bile flow
• Hematologic pruritus: This is related to blood disorders or imbalances, such as iron deficiency or polycythemia vera
• Endocrine pruritus: This type of itching is associated with hormonal imbalances in the thyroid gland 
• Pruritus and malignancy: This itching can be linked to various types of blood cancers such as Hodgkin lymphoma

Causes of pruritus

The various causes of itchy skin are outlined below. ^3,5

1. Skin disorders 

• Psoriasis – this causes dry skin to form into scales 
• Eczema  –is a common skin disorder that causes small patches of skin to be dry, cracked, and itchy
• Hives cause the sudden appearance of itchy and swollen bumps on the skin
• Dermatitis Herpetiformis – is an intensely itchy rash related to gluten intolerance (celiac disease)
• Pemphigoid – a skin disorder that typically affects the elderly

2. Medications 

• Opioids used for pain relief
• Chemotherapy used to treat cancer
• Chloroquine used to treat malaria 

Other medications that cause pruritus include:  

• Antimicrobials and antibiotics used to treat bacterial, fungal, parasitic and viral infections
• Cardiovascular medicines used to treat heart conditions 
• Metabolic medicines which help to regulate metabolic processes in the body
• Neuroleptic and psychotropic drugs used to treat psychosis 
• Steroids and hormones copy the effects of natural hormones in the body and treat various conditions. 

3. Allergies and skin reactions 

• Cosmetics such as preservatives, fragrances, hair dye, and nail varnish hardeners can cause itching
• Metals found in jewellery, such as nickel or cobalt, may lead to skin irritation and itching 
• Rubber and latex can trigger itching sensations
• Textiles: Dyes and resins present in textiles, such as clothing, can sometimes cause itching
• Plants: Certain plants including poison ivy can induce itching 
• Prickly Heat: An itchy rash commonly occurring in hot and humid weather conditions
• Sunburn: Excessive exposure to ultraviolet (UV) rays can cause skin damage and itching

4. Parasites and insect bites 

• Scabies occurs when a tiny insect digs into the skin causing scabies
• Lice can cause itching when they infest the hair or body
• Bites and stings from bees, wasps, mosquitoes, fleas, and bedbugs can trigger itching 
• Threadworms can infect the human bowels causing itchiness, particularly around the anal area
• Trichomonas vaginalis is a parasite that triggers itching by infecting the vaginal area 

5. Infections

• Viral Infections including chickenpox can lead to itching 
• Athlete's Foot: A fungal infection that specifically affects the skin between the toes 
• Ringworm: A fungal infection that results in the development of a red rash in a ring-like pattern on the skin. Additionally, it can lead to scalp itching
• Thrush in men and women is a yeast infection that affects the genital area, leading to itching and discomfort

6. Hormonal changes

Pregnancy: 

Several skin conditions can develop during pregnancy but often resolve after childbirth. These conditions include:

• Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP): A frequent skin condition during pregnancy. It is characterised by itchy, red, raised bumps that typically occur on the thighs and abdomen
• Prurigo Gestationis: A skin rash that manifests as itchy red dots and primarily affects the arms, legs, and torso
• Obstetric cholestasis: A rare disorder that affects the liver during pregnancy and causes itching without a visible rash

Menopause: 

Itching is a common symptom that can occur after menopause when a woman's periods stop due to natural hormonal changes particularly oestrogen, that is associated with aging. 

Signs and symptoms of pruritus 

While pruritus is generally considered a benign (non-cancerous) symptom, it can affect an individual’s well-being when the scratching doesn’t provide relief.⁴ This includes:

• Dry skin (Psoriasis)
• Scratch marks from itching 
• Thick and hard skin 
• Inflamed or irritated patches of the skin 
• Skin becomes disrupted and starts to bleed
• Skin becomes swollen or elevated forming a rash 
• Small raised bumps on your skin 
• Bumps filled with fluid on your skin

Management and treatment for pruritus 

The primary goal of treating pruritus is to address the underlying cause of itching.^4,6 Let's delve deeper into these options: 

Home remedies

• Keep your skin hydrated daily: Apply hypoallergenic and fragrance-free moisturisers once a day. Thicker creams and ointments such as Vaseline can work better than lotions for dry skin
• Avoid irritants that may cause itching such as cleansing agents, pet allergens, and wool or synthetic fabrics 
• Apply cold water or ice compresses to provide calming relief from itching
• Use mild soaps to minimise skin irritation
• Avoid hot baths and showers as it can exacerbate dry skin and worsen itching. Opt for lukewarm water instead

Medicines 

• Antihistamines such as diphenhydramine. It may make you drowsy which could often be helpful if you suffer from nocturnal pruritus
• Topical corticosteroids can help alleviate itching associated with inflammatory skin conditions. However, their long-term use should be limited due to potential side effects
• Capsaicin cream can help with itching in specific areas but can cause a burning feeling when you apply it to the affected area 
• Menthol and phenol creams such as Benadryl Itch Stopping Cream or Gold Bond Medicated Anti-Itch Cream
• Aloe vera: A natural plant extract that helps calm irritated skin

Therapies 

• Ultraviolet B (UVB) therapy, can be effective for uraemic and cholestatic pruritus 
• Cutaneous field stimulation (CFS) uses electrical stimulation to activate certain nerve fibres and help reduce itching
• Non-pharmacological treatments: This includes Identifying triggers, practising stress management techniques, and maintaining a healthy lifestyle to help alleviate symptoms 

Diagnosis 

To diagnose the cause of pruritus, your healthcare provider will review your medical history, conduct a physical examination, and may recommend additional tests if needed:⁸

• A full blood count can detect internal conditions like anaemia that may contribute to the itch
• Liver and kidney function tests can reveal any disorders and thyroid conditions that may be associated with itching
• Chest X-ray to check for swollen lymph nodes, which can be related to itchy skin

Complications

Severe and long-lasting itching, known as chronic pruritus, can have a significant impact on your life. It disrupts sleep, causes anxiety and depression, and can lead to skin damage, infections, and scarring due to continuous scratching. In more severe cases, it can significantly disrupt sleep and affect overall well-being. Pregnant women who suffer from obstetric cholestasis may face risks of preterm deliveries and stillbirths. Other complications include thickened skin, itchy bumps, and skin injuries that can become infected.

FAQs

How can I prevent pruritus?

To reduce the risk of itchy skin, you can protect yourself from the sun, stay hydrated, moisturise your skin, use warm water for bathing, manage chronic conditions, use a humidifier at home, and avoid known allergens.

How common is pruritus?

Around 20% of adults experience pruritus. It is also found in about 25% of people with jaundice and 50% of those receiving dialysis. Approximately 10-50% of individuals who seek medical help for pruritus have an underlying systemic disease.⁹

Who is at risk of pruritus?

The intensity and frequency of itching can vary from person to person. Certain factors such as; age, allergies, existing skin conditions pregnancy, or undergoing dialysis, can make someone more prone to itching. 

What can I expect if I suffer from pruritus?

Pruritus can cause skin irritation and discomfort, making it challenging to sleep and concentrate on daily tasks. If itching persists for longer than six weeks or is associated with an underlying condition, consult a healthcare provider for appropriate treatment options. 

When should I see a doctor?

Consult your doctor if:

• If your itchiness continues for an extended period of time, lasting beyond a few weeks
• The itching disrupts your sleep patterns 
• The treatment recommended by your healthcare provider worsens your symptoms
• Your skin appears swollen, oozes pus, or has a crusty texture, accompanied by symptoms such as nausea, vomiting, and fever, which may indicate an infection
• You experience new symptoms such as unexplained weight loss or gain, changes in bodily functions like bowel movements, fatigue, or mood changes

Summary

Pruritus is a common irritating sensation that can affect the skin. Various factors, including dry skin, allergies, medications, and underlying medical conditions can cause it. By understanding the causes and effective management strategies, individuals can find relief from itching and improve their overall well-being.