The relationships between hay fever and psoriasis
Psoriasis, also a very itchy condition, is believed to arise in the same way as eczema – that is, due to a breakdown in the skin barrier which allows allergens to pass through, stimulate the immune system to produce extra skin cells and create the cycle of barrier breakdown. Psoriasis is often present with hay fever and eczema, indicating that it, too, may have a genetic factor. Indeed, studies have shown that the condition arises in as many as 50 per cent of siblings when one parent is affected. Not everyone with psoriasis has a family history of the disorder, however.
Psoriasis can arise at any age, and both sexes stand an equal chance of developing it. The condition can occur in a susceptible person when they experience a particular trigger; such triggers may include the following:
• Psoriasis can appear at the site of a trauma – following a skin scrape, scratch or cut (such as a surgical wound), or at areas of sunburn.
• Emotional stress can cause an acceleration of the condition.
• Psoriasis is a risk factor for certain medications such as the mood-stabilizing drug lithium (brand name Eskalith) and several of the anti-malarial drugs.
• It can occur during a systemic infection – where the whole body is affected – such as influenza.
It is interesting to note that in people with psoriasis, there is a substantially lower incidence of the two main types of eczema: allergic contact dermatitis and atopic dermatitis. This strongly suggests that the immune system disturbances evident in psoriasis are different from those evident in the two types of eczema. When the genetic make-up of eczema and psoriasis are eventually discovered, we will have a better understanding of the more serious related disorders such as asthma.
Psoriasis differs visually from eczema in that there are lesions (also referred to as plaques) with well-defined edges and silvery scales that easily flake off. Beneath the scales, the skin appears shiny and red. This tends to be a lifelong condition and is characterized by bouts of flaring and clearing. A remission (where the skin is clear) may last for several months or even years.
If you have psoriasis, your dermatologist will strongly advise that you follow a daily hygiene routine to limit the possibility of bacteria invading the area of skin damage and setting up a secondary infection. Increased reddening and greater heat in the affected area and/or the presence of pus are indicators of a secondary infection. These are generally accompanied by light-headedness, fever and a general feeling of being unwell. As a skin abrasion can trigger the formation of further lesions, it is also recommended that you try hard not to scratch the area. Rubbing, picking or scrubbing the lesion should also be avoided.
In winter, humidity levels are generally lower than at other times of the year, particularly in homes with central heating. As a result the skin of a person with psoriasis may become drier and itchier. The best way to manage the condition is to use plenty of moisturizing creams, especially during the winter, paying particular attention to the areas affected by psoriasis. For the best results, the cream or ointment should be applied while the skin is still damp after washing or bathing. It is also important to pat your skin dry after bathing rather than rubbing with a towel. Many people have flare-ups of psoriasis lesions between their toes and they should, at all costs, avoid pulling a towel to and fro between their toes.
Your doctor will probably prescribe certain skin-softening preparations, as well as a steroid cream. In more severe cases, medication may also be prescribed, such as methotrexate (brand name Rheumatrex) and ciclosporin (brand name USAN).