psoriasis Flashcards
Definition
Chronic, Autoimmune inflammatory disease that involves hyperproliferation of the keratinocytes in the epidermis, with an increase in the epidermal cell turnover rate
Dermal inflammation & epidermal hyperplasia
T cells and neutrophils involvement + high TNF a, dendritic cells and IL-17/23
Localization
extensor surfaces: knees, elbows, scalp, lumbosacral, nails (pitting & onycholysis)
Symmetrical
Better in summer
can be found in the external auditory canals
Clinical presentation
Salomon colored plaques and silver scales above it, itchy
flexural psoriasis
Which infections and drugs can trigger psoriasis
streptococcal, staphylococcal, human immunodeficiency virus
Alcohol,iodides, steroid withdrawal, aspirin, lithium, beta-blockers, botulinum A, antimalarials, ACEI
Histological image
parakeratosis
poorly adherent stratum corneum is formed leading to the flaking, scaly presentation
hyperproliferation and abnormal differentiation of the epidermis, inflammatory cell infiltrates, and vascular dilatation
-Increased numbers of epidermal stem cells
-Increased numbers of cells undergoing DNA synthesis
-Delay in the expression of keratins 1 and 10 and an overexpression of keratins 6 and 16
-A shortened cell cycle time for keratinocytes (36 hours compared with 311 hours in normal skin)
-A decreased turnover time of the epidermis (4 days from basal cell layer to stratum corneum compared with 27 days in normal skin)
Types of psoriasis
- Psoriasis vulgaris
- Guttate psoriasis
- Pustular psoriasis
- Erythrodermic psoriasis
Psoriasis Vulgaris and what is Psoriatic triad
most common variant
Sharply demarcated and erythematous papulosquamous lesions. Papules and plaques
plaque lesion is usually circular, oval or polycyclic
Psoriatic triad: Patch –> Lamina –> Bleeding
Guttate Psoriasis
children and adolescents
preceded by an upper respiratory tract infection (strep. Pharyngitis)
Papules and small plaques
Need Throat swabs, respond well to phototherapy & Mild topical steroid
Erythrodermic psoriasis
Generalized erythema and scaling, onset is gradual or acute
previous plaques in classic locations, characteristic nail changes, and facial sparing. Alopecia can occur
Erythrodermic skin is associated with fever, rigors and lymphadenopathy: emergency
Causes: atopic eczema, drug eruptions, cutaneous T-cell lymphoma, allergic contact dermatitis, pityriasis rubra pilaris and seborrheoic dermatitis.
Treatment is supportive: liquid paraffin and mild topical steroids, ciclosporin, infliximab
Generalized pustular psoriasis-von Zumbusch
infiltration of neutrophils histologically
erythema and sterile pustules clinically
Hands and feet: Palmo-plantar psoriasis (Barbae)
What is nail psoriasis
pitting, punctual depression of the nail plat, oil spots (yellow-brown spots under the nail plate), onycholysis
Psoriatic arthritis: types and presentation
Swelling and hyperemia of small joints
Sausage digits & pencil in cup x-ray
5 types: asymmetric (mono– or oligoarthropathy), symmetrical polyarthritis (rheumatoid arthritis-like), distal interphalangeal joint disease, arthritis mutilans, and ankylosing-spondylitis–like
Complications of psoriasis
- Secondary infections
- Possible increased risk of lymphoma
- Possible increased risk of cardiovascular and ischemic heart disease
- Mitral valve prolapse
Diagnosis
Auspitz sign, Kobner phenomeon
Immunohistological exam: thick epidermis, elongated rete ridges, absent granular cell layer, parakeratosis, Munro microabscesses sterile neutrophilic infiltrate in stratum C.
ESR is elevated in pustular and erythrodermic psoriasis
Uric acis elevated in pustular
Managment of local psoriasis
- salicylic acid used to remove the scales first (keratolytic)
- Local: topical steroids (clobetasol, betamethasone), calcipotriene (Vit D3 analogues), retinoids (tazarotene or acitretin _ <30% involved, skin atrophy in a side effect to steroids
- Saltwater baths, climatotherapy, balneotherapy, Moisturizers
