Dandruff

Dandruff  definition

Dandruff is common scalp disorder is refers to the shedding of dead skin cells from the scalp. Dandruff should not be confused with a simple dry scalp. Most cases of dandruff can be easily treated with specialised shampoos. There is, however, no true cure. It affect half of the population.

Causes

As the epidermal layer replaces itself, cells are pushed outward where they eventually die and flake off. For most individuals, these flakes of skin are too small to be visible. certain conditions cells are goes to unusual rapid especially in the scalp. For people with dandruff, skin cells may mature and be shed in 2–7 days, as opposed to around a month in people without dandruff. The result is that dead skin cells are shed in large, oily clumps, which appear as white or grayish patches on the scalp, skin and clothes.

Dandruff is formed due to these factors,

1. Skin oil commonly referred to as sebum or sebaceous secretions.
2. The metabolic by-products of skin micro-organisms (most specifically Malassezia yeasts)
3. Individual susceptibility

In older days fungus Malassezia furfur as the cause of dandruff. While this species does occur naturally on the skin surface of both healthy people and those with dandruff. Later the specific fungus is responsble for scalp named as, Malassezia globosa, It metabolizes triglycerides present in sebum by the expression of lipase, resulting in a lipid byproduct oleic acid (OA). During dandruff, the levels of Malassezia increase by 1.5 to 2 times its normal level.

Treatment

Shampoos use a combination of ingredients to control dandruff. The pathogenesis of dandruff involves hyper proliferation of keratin cites, resulting in deregulation of keratinization. The corneocytes clump together, formed as large flakes of skin. Essentially, keratolytic agents such as salicylic acid and sulphur loosen the attachments between the corneocytes and allow them to get swiped off.

Regulators of keratinization

Zinc pyrithione (ZPT) heals the scalp by regulating the epithelial keratinization or sebum production or both.Significant reduction in the number of yeasts after use of ZPT, which is an antifungal and antibacterial agent The population of Malassezia decreases, parakeratosis gets eliminated and corneocytes lipid inclusions are diminished.

Steroids

The parakeratotic properties of topical corticosteroids depend on the structure of the agent, the vehicle and the skin onto which it is used. Corticosteroids work via their anti-inflammatory and antiproliferative effects

Selenium sulfide

It is believed that selenium sulfide controls dandruff .Its anti Malassezia effect rather than by its antiproliferative effect, although it has an effect in reducing cell turnover. It has anti-seborrheic

properties as well as cytostatic effect on cells of the epidermal and follicular epithelium. The excessive oiliness after use of this agent has been reported in many patients as adverse drug effect.

Coal Tar

Coal tar is a keratoplastic agent causing the skin to shed dead cells from the top layer and slow skin cell growth.

Imidazole antifungal agents

Imidazole antifungals such as ketoconazole act by blocking the biosynthesis of ergosterol, the primary sterol derivative of the fungal cell membrane. Changes in membrane caused by ergosterol depletion or incompatible with fungal growth and survival.

Ketoconazole is a broad spectrum, antimycotic agent that is active against both Candida and M. furfur . Of all the imidazoles, ketoconazole has become the leading contender among treatment options because of its effectiveness in treating seborrheic dermatitis as well.

Hydroxypyridones

In contrast to the imidazole antifungals, the hydroxypyridones do not affect sterol biosynthesis; instead they interfere with the active transport of essential macromolecule precursor, cell membrane integrity and the respiratory process of cells. Ciclopirox is widely used as an anti-dandruff agent in most preparations

Neem

Neem has anti-fungal properties that can be effective in treating dandruff.

Black Pepper

Black pepper contains the dandruff fighting minerals zinc and selenium. In Indian traditional Ayurveda, powdered black pepper has been used to treat dandruff.Egg oil is also treat dandruff.

Sandalwood

Sandalwood and Lemon: Application of an emulsion prepared with the oil of sandalwood and lemon juice has been proven effective to cure dandruff. In traditional Ayurveda, sandalwood has many benefits. Its main component beta-santalol (~90%) has antimicrobial properties.