Rr 24 Skin Disorders Part 06

Front 1

Describe the epidemiology of psoriasis

Back 1

1. Afflicts 1-3% of the world population
2. Strong human leukocyte antigen (HLA) relationship
3. Peak age of onset is bimodal
-Adolescents and 60yo
4. No gender difference

Front 2

Describe the pathogenesis of Psoriasis

Back 2

1. Unregulated proliferation (hyperplasia) of keratinocytes
a. Genetic factors involved (30% of cases)
b. Aggravating factors
2. Microcirculatory changes in superficial papillary dermis

Front 3

What are the aggravating factors for psoriasis?

Back 3

1. Streptococcal pharyngitis
2. HIV
-Sudden onset of psoriasis is highly suspicious for HIV
3. Drugs: lithium, beta-blockers, NSAIDs
4. Scratching the skin (Koebner's phenomenom)

Front 4

Describe the clinical presentation of psoriasis

Back 4

1. Well-demarcated, flat, elevated salmon-colored plaques
a. Covered by adherent white to silver-colored scales
-Pinpoint areas of bleeding occur when scales are scraped off
b. Rash commonly develops in areas of trauma (elbows, lower back)
-Called Koebner's phenomenom

2. Pitting of the nails

Front 5

Describe the microscopic findings of psoriasis

Back 5

1. Hyperkeratosis and parakeratosis
2. Elongation of rete pegs
-Downward extension of basal layer
3. Extension of papillary dermis close to the surface epithelium
-Blood vessels in dermis rupture when scales are picked off (Auspitz sign)
4. Neutrophil collections in the stratum corneum
-Called Munro microabscesses

Front 6

Describe the treatment of psoriasis

Back 6

1. Topical high-potency corticosteroids
2. Topical calcipotriene (vitD analog)
3. UVA plus psoralen applied to plaques
4. UVB plus coal tar applied to plaques
5. Retinoids
6. Systemic treatment
-Methotrexate, cyclosporine

Front 7

Describe the clinical presentation of psoriasis

Back 7

1. Well-demarcated, flat, elevated salmon-colored plaques
a. Covered by adherent white to silver-colored scales
-Pinpoint areas of bleeding occur when scales are scraped off
b. Rash commonly develops in areas of trauma (elbows, lower back)
-Called Koebner's phenomenom

2. Pitting of the nails

Front 8

Describe the microscopic findings of psoriasis

Back 8

1. Hyperkeratosis and parakeratosis
2. Elongation of rete pegs
-Downward extension of basal layer
3. Extension of papillary dermis close to the surface epithelium
-Blood vessels in dermis rupture when scales are picked off (Auspitz sign)
4. Neutrophil collections in the stratum corneum
-Called Munro microabscesses

Front 9

Describe the treatment of psoriasis

Back 9

1. Topical high-potency corticosteroids
2. Topical calcipotriene (vitD analog)
3. UVA plus psoralen applied to plaques
4. UVB plus coal tar applied to plaques
5. Retinoids
6. Systemic treatment
-Methotrexate, cyclosporine

Front 10

Describe the clinical presentation of Lichen planus

Back 10

1. Intensely pruritic, scaly, vilaceous, flat-topped papules
a. Fine white reticular pattern on the surface (called Wickham's striae)
b. Commonly located on the wrists, ankles
c. Nails are commonly dystrophic
d. Lesions develop in areas of scratching (Koebner's phenomenom)

2. Oral mucosa is often involved (50%)
a. Produces a fine, white, met-like lesion (Wickham's striae))
b. Slight risk of developing squamous cell carcinoma

Front 11

Describe the distribution of Lichen planus between the sexes

Back 11

Women are more commonly affected than men

Front 12

What is Lichen planus associated with?

Back 12

Hepatitis C

Front 13

What is the treatment for Lichen planus?

Back 13

1. Topical high potency corticosteroids
2. Antihistamines (For pruritis)
3. Systemic corticosteroids
4. Retinoids
6. Cyclosporine in resistant cases

Front 14

Describe the initial presentation of Pityriasis rosea

Back 14

Initially presents a single, large, oval, scaly, rose-colored plaque on the trunk
a. Called the "herald patch"
b. Frequently misdiagnosed as tinea corporis ("ringworm")

Front 15

Describe the clinical presentation of Pityriasis rosea

Back 15

Days to weeks after the initial lesion, a papular eruption develops on the trunk
a. Rash follows the lines of cleavage ("Christmas tree" distribution)
b. Lesions tend to be pruritic
c. Rash remits spontaneously in 2-10 weeks

Front 16

Describe the treatment of pityriasis rosea

Back 16

1. Antihistamine control pruritis
2. UV light therapy hastens resolution