Understanding Psoriasis

Psoriasis is a chronic, immune-mediated disorder with dermatologic and systemic manifestations and substantial negative effects on patient quality of life. In 2014, the World Health Organization recognised psoriasis as a serious non-communicable disease and highlighted the distress related to misdiagnosis, inadequate treatment and stigmatisation of this disease.

Epidemiology

Psoriasis affects both males and females, with earlier onset in females and those with a family history. Its age of onset shows a bimodal distribution with peaks at 30–39 years and 60–69 years in men, and 10 years earlier in women.

Causes & triggering factors

The most accepted hypothesis is that Psoriasis is an “Immune-mediated Inflammatory skin disease that manifests in a genetically predisposed person when exposed to certain environmental agents/triggers.” The triggers include:

(a)Genetics: Psoriasis has a genetic component that is supported by patterns of familial aggregation. First and second-degree relatives of psoriatic patients have an increased incidence of developing psoriasis. Risk for child to develop Psoriasis is nearly 16% if one parent has psoriasis while it gets increased to 50% if both the parents are affected.
Psoriasis exhibits phenomenon of “genetic anticipation” with a preferential “paternal effect” i.e., when disease is transmitted from father, it tends to be more severe and tends to occur at an earlier age than the parent.

(b)Koebnerization: It means that new lesions of the disease develop at sites of trauma. In addition to trauma, it can occur in response to sunburn, insect bites and sites of vaccination.

(c)Infections:Upper respiratory tract caused byBeta-hemolytic Streptococci can precipitate guttate psoriasis or may cause flare-up of existing psoriasis.

(d)Drugs:Drugs that worsen psoriasis include beta-blockers, antimalarials, NSAIDS (=pain killers), tetracyclines, valproate (=anti-seizure) and lithium (=anti-depressant)

(e)Smoking & Alcohol: Both smoking and alcohol addiction aggravate psoriasis.

(f)Psychological stress: Stress is one of the most common psoriasis triggers. At the same time, a psoriasis flare can cause stress. This may seem like an endless loop.

(g)Seasonal variation: Psoriasis experience worsening during Winters.

Clinical presentation

Clinically psoriasis may manifest in different forms:

1. Psoriasis vulgaris: Also called ‘chronic plaque psoriasis’, it corresponds to nearly 90% of psoriasis cases. It is characterised by well -defined, reddish, itchy, raised plaques covered with silvery scales. These plaques can join together and cover large areas of skin. Common sites include the trunk, scalp and limbs (particularly elbows & knees).

2. Inverse Psoriasis: Also called ‘flexural psoriasis’, inverse psoriasis affects arm pits and groins, and is characterized clinically by reddish patches with minimal or no scaling.

3. Guttate Psoriasis: Guttate psoriasis is a variant with an acute onset of small drop-like red and scaly plaques. It usually affects children or adolescents, and is often triggered by streptococcal infections of tonsils. About one-third of patients with guttate psoriasis will develop plaque psoriasis throughout their adult life.

4. Pustular psoriasis: Pustular psoriasis is characterized by multiple, white coloured sterile pustules. Pustular psoriasis can be localized (hands & feet) or generalized.

5. Erythrodermic psoriasis: It is an acute condition in which over 90% of the total body surface is erythematous and inflamed. Erythroderma can develop on any kind of psoriasis type, and requires emergency treatment.

Comorbidities in Psoriasis

Psoriasis typically affects the skin, but may also affect the joints, and has been associated with a number of diseases. Inflammation is not limited to the psoriatic skin, and has been shown to affect different organ systems. Thus, it has been postulated that psoriasis is a systemic entity rather than a solely dermatological disease. Psoriasis patients may exhibit increased blood pressure, cardiac disease, type 2 diabetes, and increased body mass index which may land the patient into ‘metabolic syndrome’.

Psoriatic inflammation of the joints results in psoriatic arthritis (PsA) which develops in up to 40% of psoriatic patients. It presents clinically with dactylitis (swelling and pain of fingers), enthesitis
(inflammation of tendons/ligaments at their sites of insertion, usually manifesting as heel-pain), and early morning back-stiffness.

Nail psoriasis is reported to affect more than half of psoriasis patients, and can present as the only psoriasis manifestation in 5–10% of patients. Nails may show pitting, white streaks (leukonychia), red streaks (splinter haemorrhages), and structural changes like separation of nail plate from underlying skin.

Treatment of Psoriasis

Psoriasis is a chronic relapsing disease, which often necessitates long-term therapy. The choice of therapy for psoriasis is determined by disease severity, comorbidities, and access to health care.

Topical therapies such as corticosteroids or vitamin D analogues (calcipotriol) are first line. Psoriasis at difficult-to-treat sites (scalp, face, nails, genitalia, palms and soles) warrants special attention due to its profound impact on function and relatively poor response to treatment.Steroids use for face or genitalia should be of low potency and limited to short-term use due to risk of skin atrophy and telangiectasia.

Second-line therapy includes phototherapy (narrowband ultraviolet B radiation (NB-UVB) and psoralen with ultraviolet A radiation (PUVA) and conventional systemic agents (methotrexate, ciclosporin and acitretin). NB-UVB has largely superseded PUVA due to risks of skin cancer with cumulative doses of PUVA.

Recent advancements include Apremilast, Tofacitinib, Fumaric Acid Esters, and Biologics.

Some helpful Tips for the Patients

● Bath/Shower:Long and hot showers can dry your skin, which can cause psoriasis to flare. So, limit your showers to 5 -15 minutes only, use warm (NOT hot)—water and a moisturizing fragrance-free soap. Within five minutes of taking a shower, apply a body moisturizer.

● Quit Smoking & Alcohol as these can aggravate psoriasis

● Maintain a healthy weight. If you are overweight, losing weight can reduce your psoriasis flares, decrease the need for psoriasis medications and improve how well your psoriasis treatment works.

● Eat a balanced diet rich in fruits, vegetables and whole grains. Try to avoid fats in red meat, cheese, fried food and processed snacks as these can trigger inflammation in the body. Fish, soybean and dietary fibres are helpful in psoriasis.

● Go for a morning/evening walk and do light exercises. These will not only keep you healthy but also can act as a ‘stress buster’.

In summary, psoriasis is a complex multifactorial inflammatory skin disease that is predominantly genetically determined and is associated with significant medical and psychosocial comorbidities. Advances in the understanding of its pathophysiology have led to an increasing number of therapeutic options that could dramatically improve the lives of individuals with psoriasis.

BY DR MIR SHAHNAWAZ

Dr Mir Shahnawaz is a Dermatologist, Laser Expert & Hair Transplant Surgeon and Director-DERMIS Skin & Hair Clinic, Bemina,Srinagar