There are multiple clinical types of psoriasis. The morphology and distribution of the lesions and severity of the disease can vary in patients with different types of psoriasis. The shape of the lesions can vary from small tear-shaped papules to pustules expressing generalized erythema and scale. The lesions can distribute to multiple locations on the body or localize in isolation. Patients may have chronic psoriasis with stable plaques or acute psoriasis with fast progression and broad distribution.³

A Psoriasis diagnosis is mainly based on the clinical signs, the morphology of the lesions, clinical observation, and occasionally skin biopsies.² Plaque psoriasis is the most common clinical type of disease with 80%–90% of psoriasis patients diagnosed with it.² The main feature of plaque psoriasis is the presence of symmetrical, erythematous plaques with silver scales.¹ The plaques can occur anywhere on the body but most commonly are found on the scalp, trunk, buttocks, and extremities.²

Psoriasis is a systemic inflammatory condition associated with multiple comorbidities. Psoriatic arthritis is the most common comorbidity, affecting up to 34% of the patients diagnosed with the disease. Other complications, including cardiovascular and psychiatric disorders, like depression, are also associated with the disease.¹

The prevalence of psoriasis varies worldwide depending on the location. However, in the United States, 2% of the population is estimated to be affected by the disease.³

References:

1. World Health Organization. (‎2016)‎. Global report on psoriasis. World Health Organization. https://apps.who.int/iris/handle/10665/204417

2. Kim WB, Jerome D, Yeung J. Diagnosis and management of psoriasis. Can Fam Physician. 2017;63(4):278-285. PMID:28404701.

3. Langley RG, Krueger GG, Griffiths CE. Psoriasis: epidemiology, clinical features, and quality of life. Ann Rheum Dis. 2005;64 Suppl 2(suppl 2):ii18-23; discussion ii24-5. doi:10.1136/ard.2004.033217