Psoriasis: Overview
Introduction and Clinical presentations
Psoriasis is a common skin infection that is usually persistent, recurrent, and immune mediated. It affects about 2 percent world population with associated negative impact on the physical, emotional and psychosocial wellbeing of the individual. No predilection for any age group. It is a papulosquamous condition with different morphology, distribution, severity and course.
Presentation is in the form of moderate or severe. In patients with moderate presentation (10 percent of the body surface is usually affected) (Ayala, 2007) while severe cases tend to affect the quality of life of the patient with several systemic conditions (Bhosle et al, 2006). No specific factors served as a determinant of the severity of the condition (Meier & Sheth, 2009, Van de Kerkhof, 2008). Scalp is found to be the most predilection sites of occurrence (Kerkhof, Hoop, Korte & Kuipers, 1998).
The clinical spectrum or features have been classified as plaque, guttate, small plaque, inverse, Erythrodermic and pustular variants (Meier & Sheth, 2009). The amount of skin involved, distribution (in cases where it affects areas like scalp, nails, face) and type of psoriasis are some of the factors that tend to determine the quality of life (Meier & Sheth, 2009). The lesion may develop at the site of trauma or injury (Koebner's phenomenon), found on the oral mucosa or tongue (geographic tongue). In progressive or uncontrolled state, it tends to result into generalized exfoliative erythroderma. Extracutaneous manifestations results in affectation of nails, mucosal membranes (seen in pustular psoriasis) and joints (psoriatic arthropathy)
Plaque psoriasis is the commonest clinical form or presentation of psoriasis. Present with sharply circumscribed, round oval plaques which may initially start as erythematous macules of less than 1cm or papules (Langley, Krueger & Griffiths, 2005). Guttate psoriasis present with erythematous papules in the form of droplets over the whole body with trunk as the commonest site (Kerkhof, 2005). Seen more in children with about 44-95% rate. Flexural (inverse) psoriasis affects inframmmary regions, perineal and axillary parts. Devoid of scales but tend to appear as the red lesion. Erythrodermic psoriasis is that which is replaced totally by erythema and scaling. Psoriasis is associated with different forms of systemic complications such as hyperthermia, protein loss and water-salt imbalance. Pustular type usually occurs as either palmoplantar pustulosis or generalised pustular psoriasis. Generalised is rare but represent active and unstable disease. The palmoplantar present with sterile disease with yellow pustules having background erythema and scaling.
Pathophysiology of psoriasis
Psoriasis is a skin disease that has a complex pathophysiology simply because of the limited understanding regarding the etiological factors. The present update on the factors associated with the condition is the genetic and immune-mediated components. Apart from this understanding regarding the pathophysiology, there are several multiple theories that have been formulated regarding the pathophysiology. If we look at this we can see that there is a long way to go in understanding the mechanism. The present understanding supports leukocyte recruitment towards the dermis and epidermis. The accumulation then stimulates keratinocyte proliferation which contributes to the formation of the disease. Another understanding has also shown that inflammatory cytokines such as the Tumor necrotizing factors also contribute to the pathogenesis of the condition. The pathway is not yet clear however, the TNF antagonist infliximab is what actually prove that there is a link (Krueger & Bowcock, 2005).
Systemic issues or conditions associated with psoriasis
Systemic complications and disease associated with psoriasis are some of the reasons that made the disease a complex chronic disorder. Psoriasis usually have this relationship with systemic conditions such as cardiovascular disease, psoriatic arthritis, psychiatric disorders, metabolic disorders, ocular diseases, lymphoma and inflammatory bowel diseases. The relative reasons for this association are not completely known but there is an understanding relating psoriasis to the fact that it tends to initiate increased risk factors toward those conditions. For instance, in the case of the cardiovascular conditions, patients with psoriasis have now been noted to have hypertension, obesity, smoking and genetics.
Treatment of psoriasis
There are different treatment protocols which help manage the condition. These treatments can be classified as; biologics, systemics, phototherapy, topicals, complementary and alternative medicine. Biologics commonly used are the tumor necrosis factor blockers such as etanercept, adalimumab, infliximab and golimumab. Systemics are methotrexate, cyclosporine and acitretin. These drugs work throughout the body and used especially for those that are usually not responsive to topical agents or UV light therapy. Phototherapy is done by using UVB from sunlight and the use of laser treatments. The topical agents are applied to the skin and purchased over the counter. They are majorly steroid but with synthetic vit D3 and Vit A.
References
Ayala F (2007). Clinical Presentation of psoriasis. PubMed.
Retrieved 15 November, 2013 from http://www.ncbi.nlm.nih.gov/pubmed/17828342
Bhosle et al (2006). Quality of life in patients with psoriasis. Review.
Retrieved 15 November, 2013 from http://www.hqlo.com/content/4/1/35
Krueger, J. & Bowcock, A. (2005). Psoriasis pathophysiology: current concepts of pathogenesis.
Retrieved 15 November, 2013 from http://ard.bmj.com/content/64/suppl_2/ii30.full
Langley, B. Krueger, G. & Griffiths, M. (2005). Psoriasis: epidemiology, clinical features, and quality of life.
Retrieved 15 November, 2013 from http://ard.bmj.com/content/64/suppl_2/ii18.full
Meier M. & Sheth P.B. (2009). Clinical Spectrum and severity of psoriasis. PubMed.
Retrieved 15 November, 2013 from http://www.ncbi.nlm.nih.gov/pubmed/19710547
National Psoriasis Foundation (2013). Psoriasis Treatment.
Retrieved 15 November, 2013 from http://www.psoriasis.org/about-psoriasis/treatments
Van de Kerkhof, Hoop D., Korte, J., & Kuipers, M. (1998). Scalp Psoriasis, Clinical Presentations and Therapeutic Management. Dermatology.
Retrieved 15 November, 2013 from http://www.karger.com/Article/Fulltext/18026
