Psoriasis: Causes and Pathophysiology

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Questions and Answers

What is a characteristic feature of psoriasis related to skin changes?

Hyperplasia of keratinocytes (correct)

Decrease in local immune activity

Increased production of collagen

Vasodilation of blood vessels

How can psychological stress impact psoriasis?

It promotes collagen production.

It triggers the release of cortisol. (correct)

It decreases keratinocyte activity.

It makes psoriasis less severe.

Which of the following diseases is NOT transmissible?

Eczema

Psoriatic arthritis

Psoriasis (correct)

Strep throat

What joint symptoms are associated with psoriatic arthritis?

Joint stiffness and swelling Signup and view all the answers

What factor is considered a modifiable risk factor for psoriasis?

Alcohol consumption Signup and view all the answers

Which type of psoriasis is often triggered by strep throat infection?

Guttate psoriasis Signup and view all the answers

What is a consequence of increased adipose tissue in people with psoriasis?

Increased production of inflammatory cytokines Signup and view all the answers

Which cytokines are primarily involved in the pathophysiology of psoriasis?

TNF-α, IL-17, IL-23 Signup and view all the answers

What is the primary cause of psoriasis?

Genetic and immune system dysfunction Signup and view all the answers

Which of the following is a common environmental trigger for psoriasis?

Stress Signup and view all the answers

How does psoriasis primarily affect the skin?

It leads to the formation of scaly, thick, silver plaques. Signup and view all the answers

What is the typical time for keratinocytes to fully mature in healthy skin?

26-30 days Signup and view all the answers

What role do T-cells play in the pathology of psoriasis?

They mistakenly attack healthy keratinocytes. Signup and view all the answers

Which cytokines are primarily involved in the inflammatory process of psoriasis?

IL-12, IL-23, IL-17, TNF-α Signup and view all the answers

What is the Koebner phenomenon in the context of psoriasis?

Exacerbation of psoriasis at sites of skin injury Signup and view all the answers

How quickly do keratinocytes proliferate in psoriasis compared to normal skin?

Approximately four to five times faster than normal skin Signup and view all the answers

Study Notes

Psoriasis

Psoriasis is a chronic, non-contagious autoimmune disease affecting skin, nails, and sometimes joints (psoriatic arthritis).
Characterized by scaly, thick, silver plaques, typically on scalp, elbows, and knees.

Cause

Likely Cause: Genetic factors and immune system dysfunction.
Autoimmune process: T-cells mistakenly attack healthy keratinocytes, leading to rapid skin cell turnover and inflammation.
Causes inflammation: T-cells become activated and release cytokines.
Genetic Factors: Family history increases risk.
Environmental Factors: Stress, infections (e.g., strep throat), skin injury (Koebner phenomenon), and medications (like lithium, beta-blockers).

Pathophysiology

Multifactorial: Involves the immune system, genetic predisposition, and environmental triggers.
Immune System Activation: Dendritic cells (DCs) activate T cells (Th1 and Th17). Activated T cells release cytokines (TNF-α, IL-17, IL-23) which recruit more immune cells and activate keratinocytes.
Keratinocyte Hyperproliferation: Cytokines increase keratinocyte production, reducing normal maturation time (26-30 days to 3-4 days).
Inflammation: Accumulation of immature keratinocytes on the surface forms scaly, silvery plaques.
Immune Cell Infiltration: T cells, neutrophils, cytokines, and chemokines increase local inflammation, attracting more immune cells leading to thickened skin plaques.

Disease Transmission

Not transmissible.
Not an infection.

Risk Factors:

Non-Modifiable Risks: Genetics, family history, and age (early-onset 16-22 years, late-onset 57-60 years).
Modifiable Risks:
- Stress
- Infections
- Skin injury
- Certain medications (beta-blockers, antimalarials, lithium).
- Smoking
- Alcohol consumption
- Obesity

Clinical Manifestations

Plaques: Well-defined, erythematous plaques with silvery-white scales on scalp, elbows, knees, and extensor surfaces.
Pruritus (itching): Common symptom.
Koebner phenomenon: New plaques develop at sites of skin trauma (e.g., cuts, burns).
Nail changes: Pitting, discoloration, and onycholysis (separation of the nail from the nail bed)
Psoriatic Arthritis: Joint pain, swelling, and stiffness (occurs in ~30% of those with psoriasis).

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Description

This quiz explores the chronic autoimmune disease known as psoriasis, detailing its causes, symptoms, and underlying pathophysiological processes. Learn about the genetic and environmental factors contributing to this condition and how the immune system plays a critical role in its manifestation.