Itchy Scalp (Scalp Pruritus): Causes, Symptoms, Diagnosis, Treatment And Prevention

Thursday, June 25, 2020, 18:26

Itchy scalp or scalp pruritus is a common problem that affects 13 to 45 per cent of the population. Itchy scalp causes frequent scratching and discomfort, and it can be either localised to the scalp or extend to other body areas [1].

Itchy scalp may be acute or chronic (more than six weeks). In this article, we will talk about what causes itchy scalp, its symptoms, diagnosis and treatment.

What Causes Itchy Scalp? [2], [3]

Many underlying conditions or diseases can cause your scalp to itch.

1. Seborrheic dermatitis

Seborrheic dermatitis is the most common cause of itchy scalp. It is characterised by scaly patches, red skin and dandruff. Dandruff, known as pityriasis capitis is a mild form of seborrheic dermatitis which causes scales on the scalp but without redness of the skin. Seborrheic dermatitis occurs as a result of the interactions of scalp skin, sebum, Malassezia fungi (yeast) and the skin's immunity.

2. Scalp psoriasis

Scalp psoriasis is another most common inflammatory skin disease which causes an itchy scalp, the body area which is most commonly affected by psoriasis. Scalp psoriasis causes reddish, scaly patches on the scalp. A study conducted on 195 psoriasis patients revealed that 58 per cent of patients reported itching of the scalp. Health experts aren't clear about what exactly causes scalp psoriasis.

3. Scarring alopecia

Scarring alopecia refers to a group of hair loss disorders that destroy the hair follicle, replace it with scar tissue and causes permanent hair loss. Scarring alopecia causes the scalp to itch.

4. Atopic dermatitis

Atopic dermatitis causes inflamed, itchy and dry skin on the scalp. Allergies, infection, dry skin, skin irritants, heat and sweat can trigger atopic dermatitis.

5. Pityriasis amiantacea

Pityriasis amiantacea is a condition that causes excessive scaling and itching of the scalp. Scalp psoriasis, seborrheic dermatitis, atopic dermatitis and tinea capitis are some of the causes of pityriasis amiantacea.

6. Tinea capitis

Ringworm, also known as tinea capitis is a fungal infection that affects the scalp and hair shafts. Ringworm is characterised as small patches of itchy, scaly skin on the scalp.

7. Head lice

Head lice cause your scalp to itch. Lice bites cause an allergic reaction which causes an itchy feeling on the scalp. However, if the infestation of the lice is light, you may not feel itchy.

Other causes of an itchy scalp include:

• Sensitive scalp
• Diabetes
• Herpes zoster
• Allergic reactions to medications
• Scalp folliculitis
• Systemic diseases like chronic kidney disease, cholestatic liver diseases, and hematologic malignancy.
• Psychological conditions such as depression, anxiety and delusional parasitosis.

Symptoms Of Itchy Scalp

Severe itching of the scalp that is often painful is an obvious symptom of itchy scalp. However, other symptoms can accompany itchy scalp, these include:

• Irritated skin
• Bald skin patches
• Dry skin
• Skin redness
• Scales or patches on the scalp
• Scalp swelling
• Scalp sores
• Low-grade fever

When To See A Doctor

If the itchiness doesn't go away within a few days and is accompanied by hair loss, pain, severe itching and itchy spots that are very sore to touch, you should consult a dermatologist immediately.

Diagnosis Of Itchy Scalp

The doctor will ask some questions to evaluate your itchy scalp. These include the onset of itchy scalp, affected areas other than the scalp, the type and severity and if you have any underlying chronic disease.

Then, the doctor will take a detailed history to understand the triggering factors of itchy scalp, which will focus on recent exposures to hair care products, hair care practices and medications. In addition, sun exposure, travel history or if you have come in contact with people who have been infected with infectious diseases will also be taken into account.

After which, the doctor will physically examine your scalp and hair area to check for skin conditions. A complete physical examination will be done on other body parts as well.

For a definite diagnosis, the doctor may further conduct tests like dermoscopy, wood's lamp examination and microscopic examination [4].

Image source:doctorheck.blogspot.com

Treatment Of Itchy Scalp

Depending on the causes of itchy scalp, the treatment is done.

• Moisturising the scalp with lotions and oily emollients (creams, lotions or ointments) containing glycerin or panthenol that helps scalp dryness.
• Use a shampoo with an optimal pH (4.5-6.0) that lowers the secretion of serine proteases that can cause an itchy scalp.
• Zinc pyrithione shampoo is used to treat seborrheic dermatitis.
• Shampoos containing menthol or camphor can bring relief from itchy scalp.
• Topical corticosteroids can bring a quick relief from itchy scalp.
• Antidepressant medications to treat psychological conditions.
• Ketoconazole, selenium sulfide, and coal tar shampoos can be used to reduce scalp inflammation [5].

Prevention Of Itchy Scalp

• Avoid using hair care products that contain chemicals and fragrances.
• Try to avoid hot-blow drying of your hair.
• Use hypoallergenic products.
• Refrain from sharing other people's comb, towels, pillowcases and helmets.

Common FAQs

Q. Why does my scalp itch at night?

A. A number of skin conditions such as psoriasis, atopic dermatitis and head lice can cause itchy scalp at night.

Q. Why does my hair itch even after I wash it?

A. This may be due to not rinsing the shampoo properly from the hair or you are allergic to the shampoo.

Q. How can I stop my scalp from itching naturally?

A. Aloe vera gel, olive oil, coconut oil and tea tree oil can stop the itching of the scalp naturally.