Skin Rashes Flashcards
What is psoriasis?
A papule-squamous disorder characterised by red, scaly plaques. The skin becomes inflamed and hyper-proliferates at about 10x the normal rate.
Who gets psoriasis?
Age of onset has 2 peaks- 16-22 yr olds and 55-60 yr olds. There is a genetic basis but this is not fully understood.
What is Auspitz’s sign?
the appearance of punctate bleeding spots when psoriasis scales are scraped off
Describe chronic plaque psoriasis
This is the most common type characterised by well defined, scaly, erythematous plaques usually seen on extensor surfaces. Lesions can be itchy and/or sore.
What is Koebner pneumonon?
New plaques occur at sites of skin trauma
Describe flexural psoriasis
Usually occurs later in life. There is often less scaling.
Describe guttate psoriasis
Raindrop like psoriasis where an explosive eruption of very small circular oval plaques appears over the trunk, usually 2 weeks after strep sore throat.
Describe erythrodermic and pustular psoriasis
Most severe types with widespread, intense inflammation of the skin. This can be life threatening.
Describe palmoplantar psoriasis
Localised pustular psoriasis confined to hands and feet, no severe systemic symptoms, usually occurs in heavy smokers.
Describe psoriatic nail disease
Usually get oncycholysis (nail separates from skin underneath it), nail putting, subungal hyperkeratosis and dystrophy.
Describe the pathology of psoriasis
Biopsy will show epidermal acanthosis and parakeratosisi due to increased skin turnover. The granular layer is often absent. Polymorphonuclear abscesses may be seen in the upper epidermis. The epidermal rete ridges appear elongated and clubbed as they fold down into the dermis.
3 complications of psoriasis?
Greatly impairs quality of life
Some 5-10% of individuals develop psoriatic arthritis
Psoriasis patients have a higher prevalence of cardio metabolic diseases
When are emollients used in psoriasis?
everyone
When are vitamin D analogues used for psoriasis?
Localised plaques. Calcipotrol used on extensor surfaces and calcitrol usually used on flexural surfaces. Need to be careful of hypercalcaemia.
When is coal tar used in psoriasis?
Anywhere- no limit but usually patients don’t like this treatment
When are steroids used in psoriasis?
Usually given in combination as there is a risk of rebound psoriasis
When is phototherapy used in psoriasis?
Usually when topical treatments have not worked
Describe systemic treatments for psoriasis
Immunosuppression by methotrexate or immune modulation by biological agents
When is dithranol used in psoriasis?
In localised plaques if patient complies, it is messy and time consuming, short contact as have to wash off and it stains patients clothes.
Define discoid eczema
Well defined probably atopic too. Staph infection is very common in this type of eczema
What is eczema?
Itchy, ill-defined, erythematous, scaly rash, lots of types
What is allergic contact dermatitis/ eczema?
Immune response to chemicals, topical therapies, nickel, plants etc.
What type of hypersensitivity is allergic contact dermatitis?
4
What investigations are done in allergic contact dermatitis?
Patch testing to diagnose contact allergy
Management of allergic contact and irritant dermatitis?
Avoid allergy or irritant, protective clothing, manage the eczema rash with same as atopic