What Works
WHAT WORKS
NEW BEAUTY INTELLIGENCE
HIGH-COMPLIANCE THERAPEUTICS
Hair creates a barrier to application that makes shampoo the easiest form of seborrheic dermatitis/dandruff treatment for most patients. Because the causative fungus must be controlled through persistent daily treatment, the cosmetic aspects of shampoo-based therapy must be acceptable to patients or compliance will be compromised.
Clinical research shows that a shampoo that cleanses, inhibits fungal growth, minimizes itching, and also provides a hair beautification benefit enhances patient satisfaction. In fact, a recent study found that 3 out of 4 women suffering from dandruff and seborrheic dermatitis would prefer to use a medicated shampoo with conditioning benefits.1
Treatment shampoo active ingredients have three primary therapeutic mechanisms:
1. Anti-fungal agents help prevent yeast growth.
2. Keratolytic cleansers break up and release scale and reduce sebum.
3. Cytostatic agents slow cell turnover.
TOPICAL ANTI-FUNGAL AGENTS
Using the measurement of minimal inhibitory concentrations (MICs) as a guideline, the most potent treatment ingredients with high intrinsic activity against the fungal cause, Malassezia, are pyrithione zinc, selenium sulfide, climbazole and ketoconazole.2, 3 Potency is important, but it is not the sole factor that determines efficacy. Other influential aspects of treatment pharmacology include:
- Delivery
- Retention
- Bioavailability
- Mildness
- Aesthetics
The most promising new research indicates that pyrithione zinc can be formulated against all of these factors most successfully.
Data presented at the 2004 Intercontinental Meeting of Hair Research Societies revealed that the bioavailability of antifungal active ingredients is critically important to therapeutic success. Additionally, the bioavailability of active ingredients can be potentiated by cosmetic ingredients in the shampoo formula.
- Pyrithione Zinc (PTZ) is a potent monographed anti-fungal agent against M. globosa. It treats seborrheic dermatitis/dandruff and provides symptomatic relief, reducing the irritation response while inhibiting the causal agent.4 The particles that comprise this anti-fungal can be engineered into flat platelet shapes to deliver optimized scalp coverage resulting in improved efficacy.
Clinical tests show that PTZ is unique among antimicrobials in its ability to reduce surfactant irritation. Surfactants, the principal cleansing component in shampoos, can cause irritant contact dermatitis. Potentiated pyrithione zinc is PTZ with improved bioavailability through the addition of cosmetic excipients such as zinc carbonate. While zinc alone has not been found to have anti-fungal activity, P&G Beauty scientists discovered adding zinc to PTZ in the form of zinc carbonate increases the PTZ's bioavailability by preventing PT dissociation from the zinc ion, thus allowing the molecule to exert maximum anti-fungal activity as demonstrated via in vitro testing. Clinical studies show that potentiating PTZ in a shampoo formula significantly increases its effectiveness at relieving the five primary symptoms commonly associated with the disorder: flaking, itch, dryness, irritation, and scalp tightness.
- Selenium sulfide has excellent anti-fungal properties and slows cell turnover. However, its cosmetic formulation flexibility is more limited than PTZ. Selenium sulfide products are generally safe and effective for seborrheic dermatitis/dandruff, but patients susceptible to hairdiscoloration need to follow directions and rinse hair thoroughly to remove all residue.
- Ketoconazole is a broad-spectrum anti-fungal agent that controls scale and itch. Formerly available only by prescription, it is now formulated in several strengths, including over-the-counter. Ketoconazole may also be prescribed orally to treat mycoses. Ketoconazole must be left on the scalp for 5-10 minutes. It is not recommended for patients under 12-years of age and should not be used on broken skin. It is often used for short-term therapy, several times a week, alternately with non-medicated shampoo.
- Climbazole, Octopirox, and Ciclopirox olamine are other examples of non-monographed antimycotic agents currently available only in select regions of the world.
TOPICAL KERATOLYTIC CLEANSER
- Salicylic acid helps remove scale. Salicylic acid is an exfoliant. Although it loosens scale and facilitates cleansing, it can be inflammatory and dry out the scalp more than necessary. While not available over-thecounter in the United States, sulfur and salicylic acid combination treatments are sometimes prescribed.
TOPICAL CYTOSTATIC AGENT
- Coal Tar A dark-colored anti-proliferative ingredient approved for over-the-counter treatment of dandruff, seborrheic dermatitis and psoriasis. It has been reported to have slight anti-fungal activity, but it tends to be less efficacious at controlling the yeast component of dandruff/seborrheic dermatitis than the common anti-fungal ingredients. is an anti-proliferative. Tar-based cleansers are generally effective against psoriatic flaking. They work by decreasing epidermal proliferation and the dermal infiltrates while reducing the number and size of epidermal cells, but they are less efficacious at controlling the yeast
component. Side effects include increased photosensitivity. Cosmetic considerations include a distinctive medicinal odor and tendency to tint lightly pigmented hair orange.
BEYOND SHAMPOO
Severe seborrheic dermatitis may require treatment with topical and oral steroids in addition to antimycotics. Identification of M. globosa increased understanding of the role the fungus plays in non-scalp dermatitis and may make it possible to reduce long-term use of costicosteroids.
FACTS ABOUT FLAKES
- Dandruff stinks. The odor is as powerful and unattractive as the clumps of shedding flakes look. In concentration, yeasty scale has an intensely smelly body odor, funkier than abandoned, unwashed sweat socks.
- Neck check? The area of the scalp just above the nape is the most under-washed scalp sector in the United States. Research shows that those who commonly shampoo in the shower pour shampoo onto the crown of the head and wash downward, usually missing the hidden back-of-the-head area, which is also less thoroughly rinsed. This is much less of a problem in Asia, where shampooing is more commonly done bending over, and cleansing products are applied to the nape area, then worked through to the forehead.
- A patient can be flake-free and still have dandruff. Itch rivals flakes as an annoying dandruff symptom. Sufferers from Barcelona to Beijing report feelings of itchy dryness (scalp is oily, but feels "tight") relieved by anti-dandruff treatment.
- Scratching makes it worse. Scratching irritates the scalp further and may cause a shower of flakes. However, massaging or brushing hair does not increase dandruff, it just loosens surface skin. Massaging the scalp in the course of lathering with a shampoo containing PTZ helps loosen flakes so that they can be rinsed away with the wastewater.
- Oily scalps feed dandruff. Dandruff thrives on oily scalps; frequent shampooing reduces oil temporarily but does not get rid of the cause. The best way to prevent dandruff is to shampoo daily with a gentle anti-dandruff shampoo.
- Patients are compliant for just 30 seconds. The average resident time for shampoo on the scalp is 30-seconds.6 Shampoos that achieve antimycosis on contact lead to more successful management of seborrheic dermatitis/dandruff.
- Anti-fungal shampoos can be formulated to be as mild as water on color-treated hair. Hair condition is not compromised by treatment even if the hair is color-treated or permed.