Psoriasis Flashcards
Which infectious pathogens can trigger psoriasis?
- Beta-haemolytic streptococci
- Staphylococcal infections
- HIV
Which drugs can trigger psoriasis?
- Beta-blockers
- Chloroquine
- Lithium
- Interferon
- ACE-Is
Which HLA subtypes is psoriasis correlated with?
- HLA-Cw6
- HLA-B17
- HLA-B57
Describe the typical appearance of psoriatic lesions.
- Few lesions appear which usually become confluent
- Well-demarcated
- Erythematous
- Silvery-white scaling plaques
- Pruritic
- Demonstrate Auspitz sign
- Demonstrate Koebner phenomenon
What is the Auspitz sign?
Small pin-point bleeding where scales have been scraped off
What is the Koebner phenomenon?
When physical stimuli or skin injury leads to development of skin lesion on previously healthy skin
Describe the typical distribution of psoriasis.
- Scalp
- Back
- Elbows (extensor surface)
- Knees (extensor surface)
What nail changes are typically seen with psoriasis?
- Nail pitting
- Brittle nails
- Onycholysis
- Oil drop sign/Salmon spot: well-circumscribed, yellow-reddish discolouration of the nail
What are the clinical features of psoriatic arthritis?
- Oligoarthritis (70% of cases)
- Spinal involvement (40%) of cases
- Onycholysis and nail pitting
- Enthesitis
- Tenosynovitis
- Dactylitis
- Arthritis mutilans: destruction of IP joints (esp DIP) and resporation of phalanges
What changes are usually seen on an x-ray of a hand in psoriatic arthritis?
- Joint destruction
- Pencil-in-cup deformity (DIPs)
What changes are usually seen on an x-ray of a spine in psoriatic arthritis?
- Joint destruction
- Syndesmophytes + asymmetric paravertebral ossification
What is the management of psoriatic arthritis?
- NSAIDs
- Methotrexate/sulfasalazine/ DMARDS (similar to RA)
- Ustekinumab/Secukinumab
What are the different cutaneous subtypes of psoriasis, and which is the most common?
- Chronic plaque psoriasis –> most common
- Flexural psoriasis
- Guttate psoriasis
- Pustular psoriasis
What is guttate psoriasis usually precipitated by?
Streptococcal infection (2-4 weeks prior to lesions appearing)
- more common in children and adolescents
Describe the appearance of guttate psoriasis.
- ‘Tear drop’, scaly papules
- Usually on trunk and arms