Skin Signs Of Systemic Disease Flashcards
What is a leg ulcer
Open lesion between the knee and ankle joint that remains unhealed for at least 4 weeks
What is the most common cause of leg ulceration
Venous blood stasis
What causes arterial ulcers
Insufficient blood supply due to peripheral vascular disease
What causes venous ulceration
Increased hydrostatic pressure in the vessels
Where do the majority of venous ulcers occur
The gaiter area
Describe venous ulcers
Shallow exudative and warm
Give some signs of venous insufficiency
Ankle swelling
Varicose veins
Haemosiderin deposition
Venous eczema
Lipodermatosclerosis
What is lipodermatosclerosis
Inflammation and fibrosis of the subcutaneous fat layer, usually in the lower legs
How does lipodermatosclerosis present
Woody texture, skin appears hardened and reddish-brown
Where do arterial ulcers tend to affect
The foot
Presentation of arterial ulcers
Punched-out appearance, cold, white and shiny skin
Clinical signs or PAD
Absent peripheral pulses, delayed capillary refill, intermittent claudication
Investigations for leg ulcers
ABPI for arterial
Bloods
Patch testing for treatments
Biopsy to check for malignancy
Management of arterial ulcers
Managed by reducing modifiable risk factors
Management of venous ulcers
Compression stockings + elevation
De-sloughing if necessary
Control pain
Complications of leg ulceration
Infection
Contact allergy to dressings and topicals
Malignant transformation
What is epidermolysis bullosa
A group of inherited disorders with blister formation in response to mechanical trauma
What are the 3 main types of epidermolysis bullosa
Simplex, Junctional and dystrophic
Investigations for epidermolysis bullosa
Skin biopsy
Management of epidermolysis bullosa
Mainly supportive
Clinical presentation of epidermolysis bullosa
Skin blisters and erosions
What is neurofibromatosis type 1
A genetic condition that causes tumours along the nervous system
Inheritance in neurofibromatosis type 1
Autosomal dominant
What causes neurofibromatosis type 1
Mutations in the NF1 gene
Main clinical sign of neurofibromatosis type 1
Cafe au lait macules
Other clinical signs of neurofibromatosis type 1
Plexiform neuroma, axillary or inguinal freckling, 2 or more lisch nodules
What mediates a type 1 allergic reaction
IgE
Routes of exposure that cause a type 1 allergic reaction
Skin contact, inhalation, ingestion and injection
Sensitisation stage of a type 1 allergy
Production of IgE by B cells in response to an initial allergen exposure
Residual antibodies mind to circulating mast cells by Fc receptors
Allergic stage of a type 1 allergy
On re-exposure, allergen will bind to IgE coated mast cells, causing degranulation of histamine etc.
Clinical presentation of type 1 allergy
Urticaria, angioedema, wheezing, anaphylaxis
What are other names for urticaria
Hives, wheals, nettle rash
What is urticaria
Very itchy lesions which appear with 1 hour of interaction with an allergen
What is angioedema
Localised swelling of subcutaneous tissue or mucous membranes
Is angioedema pitting or non-pitting
Non-pitting
What investigations confirms anaphylaxis
Serum mast cell tryptase level
Testing for a type 1 allergy
Specific IgE bloodwork
Prick testing
Challenge test
What is used to manage anaphylaxis
Adrenaline autotinjector
What can be used to help asthma in patients with allergies
Mast cell stabiliser
Name one mast cell stabiliser
Sodium cromoglycate
Long term management of a type 1 allergy
Avoidance
Antihistamines as first line
Corticosteroids as second line
3 step plan for an acute allergic reaction
Chrophenamine at first sign of reaction
Prednisolone if no resolution
Adrenaline IV if symptoms get worse: become blue or collapse
What is the inheritance in tuberous sclerosis
Autosomal dominant
How is tuberous sclerosis characterised
By a range of benign tumours in various organ systems
Earliest cutaneous signs of tuberous sclerosis
Ash leaf macules
What are ash leaf macules
Depigmented macules
Other clinical signs of tuberous sclerosis
Shargreen patches and enamel pitting
How may an infant present with tuberous sclerosis
Seizures
Tumours seen in tuberous sclerosis
Periungual fibromas
Facial angiofibromas
Hamartomas/angiomyolipomas
Bone cysts
What are periungual fibromas
Benign tumours around the nail
