Psoriasis Australia

Corticosteroids

When applied to the skin, corticosteroids reduce the activity of the immune system, thereby decreasing the inflammation and rapid skin cell turnover characteristic of psoriasis.

Overview of Corticosteroids

Corticosteroids, often referred to simply as steroids, are synthetic drugs that closely resemble cortisol, a hormone naturally produced by the adrenal glands. They have potent anti-inflammatory and immunosuppressive properties, making them highly effective in treating a wide range of inflammatory skin conditions, including psoriasis. When applied to the skin, corticosteroids reduce the activity of the immune system, thereby decreasing the inflammation and rapid skin cell turnover characteristic of psoriasis.

How Corticosteroids Work

Corticosteroids work by inhibiting the production of substances in the body that trigger inflammation. In psoriasis, they reduce the activity of T-cells, a type of white blood cell involved in the autoimmune response that causes the rapid growth of skin cells. By slowing down this process, corticosteroids help to:

  • Reduce Redness and Swelling: By suppressing the inflammatory response.
  • Decrease Scaling: By slowing the overproduction of skin cells.
  • Alleviate Itching: By calming the irritated skin.

Different Potencies of Corticosteroids

Corticosteroids come in varying strengths, classified into four main categories: mild, moderate, potent, and very potent. The choice of potency depends on several factors, including the severity of the psoriasis, the location of the lesions, and the patient’s age.

1. Mild (Class I)

  • Examples: Hydrocortisone (0.5% to 1%).
  • Uses: Suitable for treating sensitive areas such as the face, groin, and underarms, or for mild psoriasis.
  • Over-the-Counter Availability: Hydrocortisone creams are often available without a prescription.

2. Moderate (Class II)

  • Examples: Clobetasone butyrate (0.05%).
  • Uses: Used for moderate psoriasis on the body but not recommended for the face or sensitive areas.
  • Over-the-Counter Availability: Clobetasone butyrate creams are often available without a prescription.

3. Potent (Class III)

  • Examples: Betamethasone valerate (0.1%), Mometasone furoate (0.1%).
  • Uses: Effective for more extensive or stubborn psoriasis plaques on the body, particularly on the scalp, elbows, and knees.
  • Prescription Requirement: Potent corticosteroids usually require a prescription.

Very Potent (Class IV)

  • Examples: Clobetasol propionate (0.05%).
  • Uses: Reserved for severe cases of psoriasis that do not respond to less potent treatments. Used for limited periods and not recommended for large areas of the body.

Forms of Corticosteroids

Corticosteroids are available in various formulations, each designed for specific types of psoriasis and areas of the body:

    • Creams: Ideal for moist or weepy lesions. They are easily absorbed and provide a cooling effect.
    • Ointments: More occlusive, making them suitable for dry, scaly patches. They are more potent than creams but can feel greasy.
    • Lotions: Lighter and less greasy, making them suitable for hairy areas like the scalp.
    • Gels: Alcohol-based, they dry quickly and are also useful for the scalp.
    • Foams: Easy to apply, especially on the scalp or large areas of the body.
    • Sprays: Convenient for hard-to-reach areas, such as the back.

Guidelines for Use

Using corticosteroids safely and effectively requires careful adherence to medical advice. Here are some key guidelines:

  • Application: Apply a thin layer of the corticosteroid to the affected area, usually once or twice daily, as directed by a healthcare provider. It’s important to follow the prescribed dosage and not exceed the recommended amount.
  • Duration: Treatment duration varies depending on the severity of the psoriasis and the potency of the corticosteroid. Prolonged use, especially of potent or very potent corticosteroids, can lead to side effects.
  • Tapering Off: For potent corticosteroids, it’s often advisable to gradually reduce the frequency of application rather than stopping abruptly to prevent rebound flare-ups.
  • Avoiding Sensitive Areas: Use lower-potency corticosteroids on sensitive areas like the face, groin, and skin folds to reduce the risk of side effects.

Potential Side Effects

While corticosteroids are highly effective, their use, particularly over long periods or on large areas of the body, can lead to side effects:

  1. Skin Thinning (Atrophy): Prolonged use can cause the skin to become thin, fragile, and more prone to bruising and tearing.
  2. Stretch Marks (Striae): These can develop with long-term use, especially in areas where the skin is naturally thin, such as the underarms, groin, and breasts.
  3. Telangiectasia: The appearance of small, visible blood vessels on the skin’s surface.
  4. Rebound Flare-Ups: Abruptly stopping the use of corticosteroids can lead to a worsening of psoriasis symptoms.
  5. Topical Steroid Addiction: Overuse can lead to dependency, where the skin may flare up severely when the treatment is stopped.
  6. Systemic Absorption: In rare cases, especially with high-potency corticosteroids used over large areas or for extended periods, the drug can be absorbed into the bloodstream, potentially leading to systemic side effects like adrenal suppression.

Special Considerations

  • Children: Lower-potency corticosteroids are generally recommended for children due to their thinner skin and higher risk of side effects.
  • Pregnancy and Breastfeeding: The use of corticosteroids during pregnancy and breastfeeding should be discussed with a healthcare provider. Mild to moderate corticosteroids are typically preferred.
  • Treatment Rotation: To minimize side effects, doctors may recommend rotating corticosteroids with other treatments, such as vitamin D analogues or non-steroidal anti-inflammatory agents.

Combining Corticosteroids with Other Treatments

Corticosteroids are often used in combination with other topical treatments to enhance their effectiveness. Common combinations include:

  • Corticosteroids + Vitamin D Analogues: This combination can provide better control of symptoms with reduced steroid usage, thereby minimizing side effects.
  • Corticosteroids + Salicylic Acid: Salicylic acid helps to remove scales, allowing corticosteroids to penetrate the skin more effectively.

Accessing Corticosteroids in Australia

In Australia, mild corticosteroids like hydrocortisone are available over the counter, while more potent options require a prescription. It’s important to consult with a healthcare provider to determine the most appropriate corticosteroid treatment for your specific case of psoriasis.