What is Eczema?
Eczema is a form of dermatitis, or inflammation of the upper layers of the skin. It is broadly applied to a range of persistent or recurring skin rashes characterised by redness, skin edema, itching and dryness, with possible crusting, flaking, blistering, cracking, oozing or bleeding. Areas of temporary skin discoloration sometimes characterise healed lesions, though scarring is rare. Some of the common symptoms are:
- Moderate-to-severely itching skin (this symptom separates eczema from other skin rashes)
- Recurring rash - dry, red, patchy or cracked skin (in infants and toddlers, the rash usually appears on the face, elbows or knees. In older children and adults, the rash appears less often on the face, and more commonly on the hands, neck, inner elbows, backs of the knees and ankles)
- Skin weeping watery fluid
- Rough, "leathery," thick skin
- Lesions which may be infected by bacteria or viruses
What causes Eczema?
Although the exact cause of eczema is unknown, it appears to be linked to the following internal and external factors:
- A family history of eczema, asthma or hay fever (the strongest predictor) - if both parents have eczema, there is an 80 per cent chance that their children will too
- Particular food and alcohol (dairy and wheat products, citrus fruits, eggs, nuts, seafood, chemical food additives, preservatives and colorings)
- Irritants - tobacco smoke, chemicals, weather (hot and humid or cold and dry conditions) and air conditioning or overheating
- Allergens - house dust mites, moulds, grasses, plant pollens, foods, pets and clothing, soaps, shampoos and washing powders, cosmetics and toiletries.
What is Psoriasis?
Psoriasis is a non-contagious auto immune disease that affects 1.6 million of Australians (Psoriasis Australia).
Newly-produced skin cells normally mature over a period of three to four weeks while travelling to the skin’s surface to be shed. However, in skin affected by psoriasis, this process is accelerated and new skin cells reach the surface within 2–6 days. The rapidly-matured new cells mix with the old cells on the skin surface resulting in raised, inflamed, scaly, red skin lesions, known as plaques, which can often be inflamed, itchy and painful and can crack and bleed.
Although psoriasis most commonly appears on the scalp, knees, elbows, lower back, hands and feet, it can in fact develop anywhere on the skin, including genital areas, fingernails and toenails. The most common form of psoriasis is chronic stable plaque psoriasis (also known as psoriasis vulgaris) affecting 85–90% of people with psoriasis. Once a person develops psoriasis, it usually continues throughout their life, although it may get better or worse and even disappear for periods of time (Australasian College of Dermatologists).
What causes Psoriasis?
Psoriasis is an auto immune disease, meaning that it is caused by over activity of the immune system in the skin. White immune cells (leukocytes) accumulate and produce a range of chemicals, which act as if they are fighting infection or healing a wound and lead to an abnormally rapid rate of skin cell multiplication and formation of psoriasis plaques.
Although normal skin contains notable numbers of immune cells, in psoriatic skin, the leukocyte number is greatly increased and immune processes are activated. The over-produced cells in the outermost layer of the skin stack abnormally, leading to the formation of silvery white scales waiting to be shed. Blood vessels are enlarged to support the increase in cell production, leading to the redness associated with psoriasis plaques.
What are the treatment options for Eczema and Psoriasis?
- Topical corticosteroids that help reduce inflammation and itchiness. This is the most common form of eczema treatment. Most topical corticosteroids are available by prescription. However some milder strengths and non-steroidal options are available in the pharmacy.
- Using intense moisturizers in-between the steroid treatments
- Sedating antihistamines that induce sleep and reduce itchiness
- Wet bandaging that soothes the skin, reduces itchiness and helps heal lesions
- Antibiotics that treat secondary infections
- Allergy testing (prick or blood tests) that may help establish trigger factors and
- Diet modification, including seeking the advice of a dietician
- Topical treatments are creams, lotions, ointments, mousse or gels that are rubbed directly into the skin and are typically given when psoriasis is mild to moderate. The different types of topical treatments are (The Psoriasis Association):
- Vitamin D analogues
- Coal tar preparations
- Topical steroids
- Vitamin A analogues
- Phototherapy therapy
- Systemic medications