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Psoriasis

4 min read

PSORIASIS

Dr Sami Aldaham

What is Psoriasis?

  • Psoriasis is chronic inflammatory non contagious T-cell mediated disease.
  • Psoriasis may be associated with certain health related conditions as:
    1. Cardiovascular diseases
    2. Obesity
    3. Smoking
    4. Infections

Clinical features

  • Psoriasis is the most common chronic papulosquamous disease.
  • The classic lesion of psoriasis is a well-demarcated erythematous plaque with a silvery scale.
  • Removal of the scale commonly results in bleeding whish is Auspitz sign; gently remove scales - pin point bleeding

The classical presentation

Epidemiology

  • Psoriasis affects roughly 2% of the population.
  • Equal sex distribution.
  • Can occur at any age, but usually the onset is bimodal, between 20-30 and 50-60 years of age.
  • Familial cases are not uncommon.

Etiology/Pathogenesis

  1. Genetic factors
  2. Environmental trigger factors
  3. Trauma – Koebner phenomenon; C
  4. Stress
  5. Streptococcal infection
  6. Drugs – e.g. lithium, beta blockers, possibly antimalarial agents
  7. Withdrawal of corticosteroid therapy as Pustular psoriasis Z - contraindication of systemic steroids for psoriasis

Clinical Variants

  1. Psoriasis vulgaris
  2. Psoriatic arthritis
  3. Guttate psoriasis
  4. Pustular psoriasis
  5. Inverse psoriasis
  6. Erythrodermic psoriasis

Psoriatic arthritis

  • Affects between 7 to 21% of patients with psoriasis.
  • May occur prior to, concurrent with or subsequent to psoriasis.
  • More common in patients with moderate to severe cutaneous disease and those with nail involvement.

winter - tinea versicolor

Psoriasis Vulgaris

Skin scalp nail scalp at margins, without affecting hair

Nail Disease in Psoriasis

Guttate Psoriasis

red erythematous rain drops

Pustular Psoriasis

Generalized Pustular Psoriasis Localized Pustular Psoriasis

Erythrodermic Psoriasis

Koebner Phenomenon

Psoriatic Arthritis

Diagnosis of Psoriasis

  • Usually is clinically diagnosis.
  • Histopathology to confirm diagnosis and exclude other papulosquamous diseases and chronic eczemas. , tinea

Management of Psoriasis

  • Patient education: Patient should be know:
    1. The disease could be not curable.
    2. Not contagious.
    3. Psoriasis is a common disorder.
    4. The exacerbating factors.

Treatment Categorization

Before starting treatment psoriasis should be categorized into:

Localized disease

  • Topical steroid treatments
    1. Tar
    2. Corticosteroids
    3. Calcipotriene (vitamin D analogues)
    4. Tacrolimus and pimecrolimus
    5. Tazarotene
    6. Intense light or laser therapy (excimer laser 308 nm)

Generalized disease

  • Phototherapy
  • Systemic therapy
    1. PUVA and Narrow band UVB
    2. Methotrexate
    3. Acitretin
    4. Cyclosporine
    5. Biologics Z - expensive RR

Therapeutic Algorithm

Treatment with 308 nm laser

Control the aggravating factors

  1. Obesity
  2. Smoking
  3. Drugs

Differential Diagnosis

  1. Chronic Dermatitis
  2. Seborrheic Dermatitis
  3. Pityriasis rosea
  4. Lupus erythematosus
  5. Dermatophyte infection
  6. Cutaneous T-cell lymphoma (mycosis fungoides)
  7. Lichen planus

Psoriasis treatment

  • For limited psoriasis (less than 5% of BSA), topical therapies are first-line choices
    • Potent topical steroids should be used once or twice daily for thickened plaques on the body
  • For extensive psoriasis, systemic therapy is often necessary
    • Narrow-band ultraviolet B phototherapy is very helpful in guttate psoriasis

Chronic Dermatitis

Pityriasis Rosea

Secondary Syphilis

Cutaneous Lupus Erythematosus

Dermatomyositis

Dermatophyte Infection

Onychomycosis

Cutaneous T-cell Lymphoma

Case Four

Case Four: History

  • HPI: Wleed is a 15-year-old who presents with one week of small pink scaly round spots on his chest, abdomen, back, upper arms, thighs, and forehead. They itch somewhat.
  • PMH: none
  • Allergies: none
  • Medications: none
  • Family history: sister had strep throat a month ago
  • Social history: lives with mother, father and three siblings (ages 3, 7, and 9)
  • ROS: mild sore throat for past two weeks

Case Four: Skin Exam

Case Four, Question 1

  • Waleed ‘s exam shows many guttate (raindrop-like) scaly pink to bright red circinate papules. They do not follow skin tension lines, and there is no oral, palm, or sole involvement. What is the first test you should perform?

a. Fungal culture b. Potassium hydroxide (KOH) exam c. Rapid plasma reagin d. Shave biopsy

Case Four, Question 2

  • You perform a KOH exam to rule out tinea corporis, and it is negative. What is the most likely diagnosis for Waleed? a. Guttate psoriasis b. Nummular dermatitis (not associated with strep throat) c. Pityriasis rosea (follows skin tension lines) d. Secondary syphilis (can present this way and it is never wrong to order a screening test; no strep throat) e. Tinea corporis (should have positive KOH)

Psoriasis

  • Psoriasis is a common, chronic, inflammatory multi-system disease that mostly involves skin and joints
  • **Classic plaque psoriasis presents as pink to bright red well-demarcated plaques with silvery scale
    • Usually located on extensor knees and elbows
    • Commonly involves scalp, umbilicus, gluteal cleft, and nails
  • Guttate psoriasis presents as small “drop-like” scaly papules and plaques mostly on the trunk and extremities
    • Often follows group A beta hemolytic streptococcal infections

Now let’s look at a few examples of different psoriasis presentations

Classic psoriasis

Guttate psoriasis

Inverse psoriasis (in the folds)

Graph View

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