Page 55 - LECTURE NOTES

Stress - Many patients report an increase in the psoriasis severity with psychological

stress.
Trauma - All types of trauma can lead to the development of plaque psoriasis (eg,

physical, chemical, surgical, infective, and inflammatory). The development of psoriatic
lesions at a site of injury is known as the Koebner phenomenon.

Infection – An acute eruption of guttate psoriasis may be provoked by streptococcal
pharyngitis. HIV infection may be associated with increase in disease severity.

Drugs - Lithium, withdrawal of systemic corticosteroids, beta-blockers, antimalarials,

and NSAIDs may cause flare of the disease

Sunlight – although sunlight is generally considered to be beneficial for most of the

patients, strong sunlight may worsen the disease in a small minority.

Alcohol - Alcohol is considered a risk factor for psoriasis, particularly in young to

middle-aged males.
Endocrine – the disease state may fluctuate with hormonal changes. Psoriasis may

begin during puberty. Pregnancy may improve the disease while a flare may occur
during post-partum period.

Pathogenesis of Psoriasis

The alterations in psoriasis includes activation of T- lymphocytes against unknown
antigen → increased cytokine release → increased accumulation and activation of

lymphocytes and antigen-presenting cells (APCs), neutrophils which results in

increased proliferation of keratinocytes. Accelerated epidermal cell proliferation results
from recruitment of a large proportion of resting cells into the proliferative cycle.

The pathology of psoriasis reflects the underlying immune-mediated inflammation and
cellular hyperproliferation.

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