Seborrheic dermatitis

Seborrheic dermatitis is a skin condition that causes redness and scaly patches. It mainly affects areas that contain a large concentration of sebaceous glands, which produce an oily substance called sebum. These areas include the scalp, face, eyebrows, eyelids and upper chest, among others.

Seborrheic dermatitis may also cause mild itching, or a yellowish substance on the eyelashes; dandruff on the scalp is a mild form of seborrheic dermatitis.

Causes and triggers

The cause of seborrheic dermatitis is not well known, but may involve a reaction to a fungus naturally present on the skin. While anyone can develop this condition, some are more at risk than others, including men, the elderly, and those with oily skin.

Those with seborrheic dermatitis tend to experience a worsening of their symptoms during cold weather or periods of stress, or when hormonal changes or illness occur.

Treatment

Currently, there is no cure for seborrheic dermatitis, but the following measures may help manage symptoms:

• Wash regularly with lukewarm water and gentle soap.
• Wash hair frequently.
  • A medicated shampoo can be used every day at the onset of treatment then every other day once symptoms improve. Treatment can be continued for as long as necessary.
  • If symptoms do not improve after 4 to 6 weeks of using a medicated shampoo, try a different dandruff shampoo. A gentle, non-medicated shampoo may be used between medicated shampoo uses.
• Keep the skin well moisturized at all times to reduce itch.
  • Opt for moisturizing creams (e.g., Glaxal Base).
  • Apply in the direction of hair growth.
• Apply sunscreen to protect the skin from sunlight.
• Avoid triggers.
  • Manage sweating and stress.
  • Avoid heat.
• Avoid medications that worsen seborrheic dermatitis.
  • Speak to your healthcare provider to find out about the medications you are taking.

If using a medicated shampoo, here are instructions on how to use it correctly:

• Wet hair and separate into small sections.
• Lather right down to the roots and the skin of the scalp.
• Leave the shampoo on for at least 5 minutes before rinsing.
• Repeat if necessary.
• Rinse hair thoroughly.

Your healthcare provider may also recommend an antifungal cream (to kill the fungus), a hydrocortisone cream, or another cortisone-based product to apply on the affected area. Severe cases of seborrheic dermatitis may require a prescription from your doctor for an oral antifungal.

When should I see a medical professional?

• If symptoms affecting the scalp are not controlled with over-the-counter treatments.
• If symptoms are extensive or affect the entire body, or if they worsen.
• If the face or crotch are affected.

For more information:

• Canadian Dermatology Association