The pathophysiology of eczema, also known as atopic dermatitis, is a complex and multifactorial process involving genetic, immunological, and environmental factors. The exact cause of eczema is not fully understood, but it is believed to result from a combination of:
- Genetic Predisposition: There is a strong genetic component to eczema. Individuals with a family history of eczema or other atopic diseases (such as asthma and hay fever) are more likely to develop eczema.
- Skin Barrier Dysfunction: People with eczema often have an impaired skin barrier, which leads to increased transepidermal water loss (TEWL) and dry, sensitive skin. The weakened skin barrier allows irritants, allergens, and microbes to penetrate the skin, leading to inflammation and immune responses.
- Immune Dysregulation: Eczema is characterized by an overactive immune response in the skin. The immune system’s inflammatory cells, particularly T cells, release various cytokines that contribute to inflammation, redness, and itching.
- Environmental Triggers: Environmental factors such as allergens (dust mites, pet dander, pollen), irritants (soaps, detergents), climate (cold and dry weather), and stress can trigger or worsen eczema flare-ups.
Now, how can UVB therapy help in addressing eczema flare-ups?
UVB therapy works to address eczema flare-ups through its immunomodulatory and anti-inflammatory effects on the skin. Here’s how it can be beneficial:
- Immunosuppression: UVB light exposure can suppress the overactive immune response in the skin, reducing the release of inflammatory cytokines from immune cells. This helps to decrease inflammation and redness associated with eczema flare-ups.
- Reduction of Inflammatory Cells: UVB therapy can reduce the number of inflammatory cells (such as T cells) in the skin. By targeting these cells, UVB helps to dampen the immune response and limit the extent of inflammation.
- Improved Skin Barrier Function: UVB therapy can stimulate the production of certain proteins and lipids that help improve the skin barrier function. This strengthens the skin’s protective layer, reduces moisture loss, and enhances its ability to resist irritants and allergens.
- Antimicrobial Effects: UVB light has some antimicrobial properties, which can be helpful in reducing the risk of skin infections that can occur during eczema flare-ups when the skin is compromised and prone to bacterial colonization.
It’s important to note that while UVB therapy can be effective in managing eczema flare-ups, it is typically used as a second-line or adjunctive treatment for moderate to severe cases when topical treatments and other therapies have not provided sufficient relief. Additionally, UVB therapy should be administered under the supervision of a healthcare professional to ensure safety and to tailor the treatment to each individual’s needs. The frequency and duration of UVB sessions will be determined based on the severity of the flare-ups and the patient’s response to treatment.
