Coal Tar: the natural anti-inflammatory to be rediscovered

Where does coal tar come from?

Coal tar is a thick black liquid, with a characteristic odor similar to that of asphalt. It comes from the hot distillation of hard coal in cooking ovens.

Coal tar and dermatology

The anti-inflammatory properties of coal tar were identified in the mid-nineteenth century, mainly thanks to Vienna-based dermatologist, Professor Mortiz Kaposi.
Since then, this natural compound has been used to treat inflammatory skin diseases such as psoriasis, seborrheic dermatitis, and atopic dermatitis.

How does coal tar work?

This pitch derived from charcoal is composed of some 10,000 ingredients that probably interact with each other.
The true mode of action is not completely known.
It is thought to interact with cellular DNA by transiently preventing division..
By doing so, coal tar curbs the growth of the epidermal cells and reduces the skin’s lymphocytes, both of which can reduce redness, itching and inflammation.

Preconceptions

Coal tar has been labeled as carcinogenic and is currently banned in cosmetics in Europe.
Coal tar contains several polycyclic aromatic hydrocarbons (PAHs) that are believed to be carcinogenic to humans, as they have been proven to be in laboratory animals.
PAHs are found in the air, in water and in food.
The main source of PAHs is the combustion of petroleum and its derivatives.

Is coal tar really carcinogenic?

In the late 1990s, the US FDCA researched whether coal tar was carcinogenic.
Their investigation concluded that coal tar is a safe, effective ingredient to treat skin conditions.
Indeed, despite having been used in dermatology for over 150 years, there has been no proven link between coal tar and cancer.

Coal tar and photosensitivity

Coal tar causes increased skin sensitivity to ultraviolet light. Due to this, conditions such as psoriasis were often treated in the past with a combination of coal tar and UV ray application. Today, however, such treatment is no longer used due to a better understanding of the general risks of photosensitivity.

Other tars

In addition to coal tar, there are many other varieties. The best known are plant-based tars, namely pine tar, birch tar and juniper tar. These tars look and smell similar to coal mineral tar but have different properties. Plant-based tars are not anti-inflammatory and can actually cause irritation. It’s therefore very important to not confuse the different types of tar.

Use in dermatology

Thanks to recent developments in excipients, coal tar can be effectively used at very low concentrations of around 1%.
For psoriasis, coal tar is usually applied as an ointment to patches.
For seborrheic dermatitis, coal tar can be applied as a cream on the body. On the scalp, it can be used in lotion or shampoo form.
For atopic dermatitis, coal tar can be used as lotion or cream.

Application

Coal tar products should be applied in small amounts every evening and should be massaged into the area. Shampoos containing tar can be used like an ordinary shampoo.

Availability

Generally, tar-based treatments such as ointments, lotions and shampoos are available online from sites such as Amazon and Ebay. In countries including the United Kingdom, United States, Canada, South Africa and Ireland, coal tar is available for purchase in pharmacies, or can be prepared by pharmacists. On the other hand, coal tar cannot be purchased nor prepared by pharmacies in Italy.