Psoriasis Flashcards
GENETICS
What % of new cases of psoriasis are familial?
40%
What the the single Major Histocompatability Complex (MHC) locus is the strongest susceptibility locus for psoriasis?
(Strongest gene)
PSORS1
What environmental factors affect the course of Psoratic disease?
- Stress
- Infection
- Skin trauma
- Drugs
- Alcohol
What drugs are associated with worsening/developing psoriasis?
- Beta Blockers
- NSAIDs
- Lithium
- Anti-Malarials
What form of psoriasis has the strongest link with smoking?
Pustular psoriasis
What is the aetiology of psoriasis?
- T-lymphocytes & Dendritic cells produce cytokines
- These Cytokines stimulate keratinocytes
- Keratinocytes proliferate and increase inflammatory cells to the skin
- Epidermal Hyperplasia and inflammation occurs.
What are the peak decades of onset?
20-30yrs and 50-60yrs
What are the subtypes of Psoriasis?
- Thin Plaque Psoriasis
- Flexural Psoriasis
- Pustular Psoriasis
- Gutatte Psoriasis
What type of psoriasis is this?
Pustular Psoriasis
What type of psoriasis is this?
Guttate Psoriasis
What type of psoriasis is this?
Thin Plaque Psorasis
What is the commonest form of psorasis?
Plaque Psorasis
Where does plaque psoriasis most commonly appear?
- Scalp - 80%
- Elbows more than knees (75% vs 55%)
- Legs more than arms (75% vs 55%)
- Soles of the feet in 13%
If you notice psoriasis, what part of the body should you also examine.
The nails.
Look for Subungual Hyperkeratosis, Pitting, onycholysis.
What form of psoriasis is the 2nd most common form of psoriasis in adults & the most common in children?
Guttate Psoriasis
What is strongly linked to guttate psoriasis?
Streptococcal infection
What investigations should be done if you see guttate psorasis?
ASO Titres.
Check for sore throat.
What is the differential diagnosis for guttate psoriasis?
- Pityriasis rosea
- Secondary syphilis
- Rarely: pityriasis lichenoides chronica
What is the management of guttate psoriasis?
UV light.
Topical therapies don’t really work.
The plaques settle in a few weeks to a few months.
What type of psoriasis is this?
Flexural psoriasis
(AKA Inverse Psoriasis)
What type of psoriasis is this and how does it differ from cadidal nappy rash?
Napkin psoriasis
(There is clear demarcation here where as in candidal infection there are satellite lesions)
What type of psoriasis is this and what should you do as a GP?
Unstable psoriasis
- Refer as a Dermatological emergency
What type of psoriasis is this?
Erythrodermic psoriasis
- Differentials: Eczema, Drug Rection, Cutaneous T-Cell Lymphoma & Pityriasis rubra pilaris.
- Dermatological Emergency
- Biopsies are taken.