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Types, clinical manifestations and management.

What is psoriasis?

Autoimmune chronic inflam­matory diseases of the skin.
Occurs due to overst­imu­lation of immune cells that causes excessive prolif­eration of kerati­noc­ytes.
Silvery scaling of skin and itching.
Not contagious and not severe in many cases (outpa­tient mx)

General features

Erythe­matous papules and silver­y-white scaling plaques
Well demarc­ated, raised, red patches
Usually not itchy (pruritus is typically mild - 80% of cases)
Affects scalp, back, elbows and knees (extensor surfaces), and nails (thimble pitting).
Erythe­matous- superf­icial redness caused by dilation of capill­aries.
Nail pitting - small, round depression in the nail.

Clinical variants.

Plaque psoriasis
Well demarcated individual thick, scaly, erythe­matous lesions
Guttate psoriasis
numerous small, scaly, red or pink, tear-drop shaped lesions
Psoriatic nail disease
Drug-i­nduces psoriasis
Psoriatic arthritis
Inflam­mation of joints on hand, feet and spine that can occur with psoriasis
Pustular psoriasis
appears as red bumps filled with noninf­ectious pus (pustules)
Flexur­al/­inverse psoriasis
occurs in skin folds and flexor surfaces creases of joints
Erytho­dermic psoriasis
genera­lized erythe­matous lesions.
Scalp psoriasis
affects the scalp

Plaque Psoriasis

Most common type
Thick, scaly, erythe­matous lesions
Lesions are red with silver­-white scaling
Common sites:
Extensor surfaces of elbows and knees.
Lower back
Scalp (can cause temporary hair loss)
Nails- pitting and onycho­lysis
Onycho­lysis - separation of the nail from the nail bed

Guttate Psoriasis

Often preceded by Strept­ococcal infection (Strept­ococcus pharyn­gitis)
Resolves quickly

Erythr­odermic Psoriasis

There is increase in cutaneous blood flow, heat loss, and water loss
Skin becomes red.
Scaling is absent (although this can proceed the erythr­ode­rma).

Invers­e/F­lexural Psoriasis

Common sites:
Genitals (between thigh and groin)
Under an overweight abdomen (panni­culus)
Under the breasts (infla­mmatory fold)
Increased by friction and sweat
Vulnerable to fungal infections
Looks like smooth inflamed patches on skin

Psoriatic arthritis

Joint and Connective tissue inflam­mation.
Most common joints affected:
Fingers and toes
Results in Dacylitis
Other joints:
Knees, hips, spine (spond­ylitis)
Morning stiffness of affected joints
Dacylitis - Sausage shaped swelling of fingers and toes.

Pustular psoriasis

Can be localized, common to hands and feet
Palmop­lantar pustulosis
Or genera­lized, widespread patches


Precip­itating factors
1. Infections
Pharyn­gitis, HIV
2. Drugs
Beta blockers, anti-m­ala­rial, lithium, NSAIDs, systemic steroid withdrawal
3. Alcohol and smoking
4. Emotional stress
5. Local trauma


Mild (3% of the body)
Moderate (3-10% of the body)
Degree of severity is based on:
proportion of body surface area affected
disease activity (plaque, redness, scaling)
response to previous treatments
impact of the disease in the patient


Based on appearance of the skin
Skin biopsy, or scrapping - to rule out other disorders
Biopsy shows clubbed rete pegs if positive for psoriasis
Auspitz sign
small pinpoint bleeding when scales are scraped off


Mild disease
Mild-t­o-m­oderate disease
Topical cortic­ost­eroids (triam­cin­olone, fluoci­nonide, clobet­asol), emollients, topical retinoids (tazar­otene), vitamin D analogs (calci­pot­riene, calcit­riol)
For facial areas
Topical tacrolimus and Pimecr­olimus
Photot­herapy, MTX, cyclos­porine, anti-T cell agent, anti-TNF agent

Vitamin D analogs

Avoid use on delicate skin areas (face, flexures) because of irrita­tion.
Combine with steroids to increase efficiency

Coal Tar

Anti-i­nfl­amm­atory, anti-p­rur­itic, anti-m­itotic

Systemic Therapies

For severe genera­lized psoriasis intolerant after topical therapy
S/E: hepatic fibrosis, myelos­upp­res­sion, terato­genic
S/E: myelos­upp­res­sion, skin reactions, liver toxicity, terato­genic
S/E: renal toxicity, HTN, gingival hypert­rophy


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