Dandruff (Itchy scalp)

 Dr K S Prasanna, Dermatologist, Institute of Applied Dermatology, Uliathadka, Kasaragod

Dandruff, or itchy scalp, is a common relapsing problem, limited to the scalp with high sebum(oil) production. It is nothing but flaking of scalp skin with or without itching. It is a disease that has existed for centuries despite several treatment options. The scaly scalp may look unhygienic and untidy with a bad odour. It could make the sufferer feel self-conscious and embarrassed. Itching of the scalp due to dandruff also causes great embarrassment to the sufferer. It has been observed that dandruff occurs mainly between puberty to middle age, the phase where sebaceous glands are more active. Several studies on the prevalence of dandruff across the world have shown a prevalence of up to 50% in the general population.

The triggering factor (cause) could be microbial and non-microbial. Microbial cause is a yeast(fungus) called Malassezia furfur. The scalp PH is 5.5.and that of the hair shaft is 3.67. The scalp is unique among skin areas. It is characterized by a thick skin layer with high follicular density and abundant sebaceous glands. The presence of these glands along with dark, warm environment of the scalp makes it more prone to yeast infection as well as head lice. Degradation of sebum triglycerides to oleic acid and arachidonic acid is the primary mechanism by which fungi causes dandruff.

  Non microbial causes are sunlight exposure, dry scalp and excessive sebum production. Studies have shown that decrease in Ceramide i and increase in ceramide 6i and 6ii in the stratum corneum and increased dandruff occurrence have been reported. Mild oiling of the scalp with coconut oil helps to maintain skin barrier function and trans epidermal water loss. And in addition, coconut oil contains lauric acid which has antifungal activity. But excessive oiling itself can cause dandruff. The other nonspecific causes of dandruff are frequent combing and shampooing. This is known to cause scalp stratum cornium barrier impairment and thus increase in dandruff. Dirt accumulation due to less frequent shampooing also causes dandruff.

Treatment  - Long term treatment is mandatory in order to control dandruff. It includes various shampoos. The list goes like this

1. Zinc pyrithione- 1%- burning and stinging sensation if it gets into the eyes, mouth or nose is the side effect.

2. Ketoconazole -2%- mild skin irritation dry skin or headache are the side effects in some people.

3. Selenium Sulphide -1-2.5 %-Unusual oiliness, dryness of hair and scalp discoloration are some of the side effects.

4. Keratolytic agents like Salicylic acid - Dry peeling, burning and stinging at the application site are the side effects

5. Antiproliferative like Coal tar-0.5-3%- Scalp irritation and staining of the skin are the side effects.

6. Piroctone olamine-0.5-1%- Acts by inhibiting the degradation of serum triglycerides to oleic acid and arachidonic acid. Thus, the inhibition of this mechanism itself helps in treating dandruff. It is available as a leave on lotion (molecular replacement therapeutics-MRT). It is an innovative proprietary platform technology, developed by Vyome therapeutics limited, which changes the composition balance of the fungal membrane, leading to its disruption and clearance. It is also available in shampoo form.

Method of application of shampoo and lotion

Shake the bottle well before use. Lather the scalp with shampoo and leave it for five minutes. Apply it daily for one or two weeks depending on the severity of the dandruff and later on twice a week. Be care full while using coal tar shampoo, which can discolour blonde, grey or white hair. Coal tar shampoo also makes your hair sensitive to sunlight. Don’t use it in case of scalp infection. Avoid contact with eyes. Wash immediately with water in case of any accidental contact.