Itchy Scalp

1 Itchy Scalp Summary

Itchy scalp also known as scalp pruritus is a very common complaint and causes a lot of distress. Pruritus or itching creates an itch-scratch cycle in which scratching makes the scalp itchier, and this, in turn, leads to further scratching of the scalp.

It may be caused by a scalp condition or by an underlying problem in the body. The itching may be localized or generalized. In some cases, the itchy scalp is associated with other symptoms like scabbing and flaking of skin. In some other cases, this may remain without any other changes in the skin.

It is a general consensus that itchiness of scalp is due to dandruff. But, there are several other conditions may lead to itching in the scalp like a bacterial infection or autoimmune conditions. The causes include a variety of dermatologic, systemic, neurologic, and psychogenic issues. Thus, scalp pruritus is classified based on the underlying cause of the condition.

Dermatologic – in this type, the scalp condition arises from diseases of the skin like inflammatory skin conditions, infections, autoimmune conditions, and neoplasms of the skin.

Neuropathic – neuropathic type of itchy scalp arises from diseases and disorders of the nervous system. Some of the causes of the neuropathic itchy scalp are diabetes mellitus, migraine, atypical facial neuralgia, brain and spinal cord injury, and tumors of the brain.

Systemic – systemic scalp pruritus arises from diseases that affect different organs. Conditions like chronic renal failure, dermatomyositis, and drug-induced pruritus are some of the causes of itchy scalp.

Psychosomatic or psychogenic – it is also known as somatoform pruritus and is usually associated with psychiatric and psychosomatic diseases. Many obsessive compulsive disorders, tactile hallucinations, and anxiety disorders may result in itchiness of the scalp.

Some of the common symptoms that are seen to be accompanying itchy scalp are: 

  • Patches of bald scalp
  • Irritation of skin
  • Fever
  • Dry skin
  • Sores filled with pus
  • Redness of scalp
  • Scalp scales
  • Swelling in scalp
  • Sores on scalp

In many cases, itchiness of scalp may resolve within few days. If scalp itching is associated with pain, hair loss, and severe itching, doctor’s advice is recommended. Causative fungal infection and lice infestation may need medical treatment for resolving itchiness.

Treatment of the symptom depends on the cause of itchiness. Special topical agents are suggested for controlling dandruff, one of the most common causes of scalp itchiness. Scalp medications help in reducing oil content on the scalp or kill the causative fungus.

Azole agents, coal tar, and salicylic acid are commonly used as scalp medications. An itchy scalp may also be an allergic reaction to any of the hair products. Stopping the use of the product helps to reduce itchiness.

Pediculicide is recommended for controlling head lice. Washing the hair regularly with warm water without using products that contain dyes and chemicals helps to prevent scalp pruritus.

Washing of hair helps to reduce the accumulation of oil on the scalp. Avoiding physical contact with people with lice infestation or fungal infection helps to prevent the spread of these conditions.

2 Causes

A number of dermatologic, systemic, neurologic and psychogenic diseases are implicated in the development of itchy scalp. Scalp pruritus is classified on the basis of underlying disease.
Dermatologic scalp pruritus develops from diseases of the skin.

The different dermatologic causes in order of frequency of occurrence are: 

  • Inflammatory skin diseases – this includes seborrheic dermatitis, psoriasis, advanced aging itch and skin xerosis.
  • Infections – this includes mycotic, bacterial and viral infections and scabies.
  • Autoimmune conditions – dermatitis herpetiformis is an autoimmune skin condition that leads to scalp pruritus.
  • Neuropathic skin conditions – dermatologic causes in this type arise from diseases and disorders of the nerves. Injury to the brain and spinal cord, migraine, atypical facial neuralgia and diabetes mellitus are some of the common causes.
  • Systemic conditions – have their origin in the different diseases of organs. This includes chronic renal failure, cholestatic liver disease, and drug-induced pruritus.
  • Psychosomatic/psychogenic – these are pruritus that develops in association with psychiatric and psychosomatic diseases.

Seborrheic dermatitis or dandruff is one of the most common causes of itchiness of scalp. Studies show that the levels of histamine in the scalp is high in patients with this condition. Reducing the level of histamine will help in itching and pain associated with the condition.

More than half of the patients with scalp psoriasis suffer from an itchy scalp. But, in this case, the itching was limited to regions of psoriatic lesions. It is also common in people with lichen planopilaris, a condition characterized by inflammation that leads to progressive and permanent hair loss.

The neuropathic itch of the scalp is associated with conditions like diabetes mellitus and herpes zoster. Control of diabetes reduces the itching.

The sensitive scalp is yet another cause of itchiness in the scalp. People with sensitive scalp have complaints of discomfort in the scalp due to the nagging urge to itch but lack any visible signs of scalp irritation. Scalp sensitivity is associated with considerable hair loss.

Some other important, but less common, conditions for itchiness of scalp are dryness of scalp, not washing enough, lack of adequate exfoliation, reaction to certain hair cleansing products, healing sunburn, and a subpar diet.

It is common that the scalp dries up during winter and fall, and worsens itchiness. Not washing the hair regularly may lead to a buildup of oil and dead skin cells in the scalp. The presence of both these causes flaking and itching.

Even when the hair is washed often, proper exfoliation to remove the buildup is very important in reducing itching. Using an appropriate tool to remove the buildup prevents irritation and itching.

Using a new hair cleansing or cosmetic product may cause and allergic response, leading to scalp pruritus. Dryness and itching of the scalp may also be caused by low levels of vitamin B, D, fats, and zinc in the diet.

When the scalp heals after a sunburn it may flake off. The healing is also associated with itching. Frequent heat styling of hair may also lead to scalp itchiness. This condition is called as hot comb alopecia. Scalp pruritus may also be a symptom of an anxiety disorder.

3 Diagnosis and Treatment

Scalp examination is one of the first steps in the diagnosis of the reason for itchiness of scalp. The skin may show changes like swelling, reddishness, rash, or discolorations.

The doctor may also ask for circumstances that might lead to an allergic response like scalp itching. For example, a change in the hair cleansing product. Vital signs including body temperature and body weight also may indicate possible causes of scalp itch.

Body temperature rises with infections and in some types of cancers. Weight loss may be indicative of stress, malabsorption, and some cancers. Scalp examination reveals the presence of parasites and changes in the skin.

Other tests are recommended when the obvious cause of itchiness is not revealed by medical history or physical examination.

Blood tests – White blood count will be increased in infections and leukemia, while erythrocyte sedimentation rate and CRP are elevated in infections and some malignancies.

An elevated level of glucose reveals diabetes. Kidney failure is indicated by urea in the blood. Malabsorption and reduced level of zinc and Vit A are also revealed by blood tests.

Other tests include chest x-ray, urine analysis, and abdominal ultrasound. Urine analysis is useful in revealing diseases of liver and kidney. Skin tests are suggested to check for allergies.

Temporary discontinuation of a particular product is also suggested to check for side effects or allergies to the same. A skin biopsy may be suggested in some cases where a sample of skin is removed and investigated under a microscope.

As in the case of many other symptoms, treatment depends on the causes. For seborrheic dermatitis or dandruff, washing with topical agents is the most accepted form of treatment. The medications may help to reduce or remove oil buildup in the scalp or destroy the fungus.

Some of the common scalp medications used are:

  • Pyrithione zinc
  • Sodium sulfacetamide
  • Azole agents
  • Coal tar
  • Topical terbinafine
  • Keratolytics

Pediculicide is the recommended medication for removing lice infestation in the scalp. Active lice may also be removed using a fine-tooth comb.

Medication helps to destroy the eggs of lice stuck on the hair. Preventive treatment is suggested for people who live in close colonies. Clothes, bedding, and other personal materials should be washed and dry cleaned.

Hair should be washed regularly to remove the oil buildup on the scalp. The water used for washing should be warm enough so as to not irritate the scalp. Hot water may lead to dryness in the scalp.

Remember to exfoliate the scalp to remove the buildup of oil on the surface. Avoiding products that contain chemicals, dyes and fragrances help to prevent allergic reactions.

Physical contact with people who have lice or fungal infections should be completely avoided. This will also help to prevent the spread of these organisms to other people. Sharing or combs, brushes, towels, and helmets should be avoided.

For itchiness caused by the healing of sunburn in the scalp, deep conditioners or soothing products may be of help. Having a healthy diet with Vit B, D, and zinc prevents dryness of scalp and itchiness.

4 Related Clinical Trials