What is the epidemiology of psoriasis?
- 1-3% of the population
- Less common in blacks
- Even distribution between genders
What is the clinical presentation of plaque psoriasis?
- MOST Common type
- Erythematous (red) plaques with "silvery" scale.
- Most patients have chronic localized disease, but there can be systemic manifestations
- Affects the extensor (outside) more than the flexor (pits)surfaces
- Usually not on face, palms, soles of feet
What is the etiology of psoriasis?
- Genetics contribute: 40% have PSORS1 locus in the MHC I region
What is the pathophysiology of psoriasis?
- An unknown antigen may inappropriately trigger the APC cells and falsely initiates T-cell activation = cytokine and growth factor overproduction = migration of T-cells to the skin resulting in:
- increased turnover rate of epidermal cells (keratinocytes)
- increased numbers of epidermal stem cells
- abnormal differentiation of skin cells (thickened skin)
- decreased cell turnover time (37h vs 300h)
What are the risk factors/exacerbating factors for psoriasis?
- Streptococcal infections
- Overuse of alcohol
- Psychological stress
- Trauma to the skin (scratching, sunburn, or surgery)
What are the complications of psoriasis?
- Itching may be experienced and can be severe
- Impaired mobility and daily functioning
- Psychological stress
- Reduced QOL
- Infection (Skin and soft tissue, sepsis)
What are the non-pharmacological options for treating psoriasis?
- Avoid excessive alcohol consumption
- Soaking baths to remove scale, followed by emollient use
- Psychological stress reduction
- Sun exposure (avoid sunburn)
- Phototherapy (UVB and PUVA)
How is UV light used for treatment of psoriasis?
- safest treatment for extensive psoriasis in pregnancy
- can be combined with Calcipotriene, Tazarotene, Coal tar, or Anthralin
- UVA plus Psoralen
- UVA penetrates deeper and doesn't burn as readily as UVB
- using PUVA plus retinoids (Tazarotene, Acitretin) to reduce dose of PUVA
What are the SE of PUVA?
- Burning sensation
- Photosensitivity (use eye protection with PO Psoralen until eliminated from body)
What are the topical agents used for psoriasis?
- Salicylic acid
- Topical Corticosteroids
- Calcineurin inhibitors (Tacrolimus, Pimecrolimus)
- Vitamin D analog (Calcipotriene)
- Retinoid (Tazarotene)
- Coal tar
What are the systemic agents used for psoriasis?
- Cyclosporine, Tacrolimus
- Retinoid (Acitretin - DON'T use this)
- Sulfasalazine (Psoriatic arthritis only)
What are the immunomodulatory agents used for psoriasis?
- Etanercept (TNF)
- Infliximab (TNF)
- Adalimumab (TNF)
- Alefacept (LFA-3)
- Ustekinumab (IL-12, IL-23)
What are the SE of salicylic acid in psoriasis?
- Burning and stinging of applied areas
- Large area application:
- Hyperventilation (occasionally)
What is the advantage of topical calcineurin inhibitors (Tacrolimus, Pimecrolimus)?
Desirable for use on face and intertriginous areas (thin-skinned)
What are the SE of Vitamin D analog (Calcipotriene)?
- Skin irritation
- Burning and stinging
- Worsening of psoriasis sx (rare)
What are the SE of topical Retinoid (Tazarotene)?
- Teratogenic (Do not apply to more than 20% of body surface area)
- Burning and stinging
- Dry skin
- Skin pain
- Worsening of psoriasis
What are the SE of Coal tar and Anthralin?
- Staining of skin
What is the MOA of Salicylic Acid in psoriasis?
Remove scale, smooth the skin, and decrease hyperkeratosis
What is the MOA of vitamin D analog (Calcipotriene) in psoriasis?
Inhibits growth and differentiation of keratinocytes by binding the vitamin D receptors in the epidermis
What is the MOA of topical retinoid (Tazarotene) in psoriasis?
Interacts with the retinoic acid receptor to control symptoms
What are the SE of systemic retinoid (Actretin)?
- Teratogenic (3yrs after DC!)
- Renal toxicity
- Hypervitaminosis A (dry lips, mouth, nose, eye, skin; pruritis, scaling, and alopecia)
- Hyperlipidemia (esp triglycerides)
- Electrolytes abnormality
- Skeletal/bone changes
- Increased intracranial BP when used with TCN
What is the MOA of systemic retinoid (Acitretin) in psoriasis?
Unknown, but works by interacting with the retinoic acid receptor
What are the special considerations for systemic retinoid (Acetretin)?
- Do not donate blood for 3yrs after DC
- Use at lease 2 forms of birth control
Which biological agent has the quickest onset of action in psoriasis?
Which biological agent has the best SE profile?
Which biological agent has the most convenient dosing schedule for psoriasis?
Which biological agent has the slowest onset of action in psoriasis?
Which biological agent has a restricted distribution (only found in physician offices and specialty pharmacies)?
Which biological agent is contraindicated in HIV patients?