DISEASES Flashcards
- skin fragility (minor knocks produce erosions on hand)
- itching and burning precedes blisters on sun exposed skin
- on dorsum of hands, face and upper chest…
- haemorrhagic vesicles
- bullae
- crusted erosions
- superficial scars
- milia
- hyperpigmentation
- hypertrichosis
- solar uticardia
- normal teeth unlike congenital erythropoietic porphyria
- normal mucosa unlike some other autoimmune blistering diseases
- Porphyria cutanea tarda PCT type 1
investigations for porphyria cutanea tarda?
- urine and stool samples (measure porphyrins)
- urine fluroesces bright pink under UVA lamp
- biopsy a fresh blister
- rule out hepatitis C risk factors
- withdraw precipitating factors i.e. alcohol and oestrogens
causative factors of porphyris cutanea tarda?
- alcohol
- oestrogens
- hepatitis C
- haemochromatosis due to iron
- advise strict sun protection
treatment for porphyria cutanea tarda?
- low dose HCQ (hydroxychloroquine)
- regular venesection every 2 weeks for 3-6 monts to decrease ion stores
what enzyme defect causes erythropoietic protoporphyria?
ferrochelatase enzyme
- mostly enzyme ability is just reduced
- rare form of porphyria that presents in childhood
- babies cry bitterly within minutes of sun exposre
- signs are subtle, skin is basically normal between episodes
- Baby feels like its burning but cant communicate it
- 2% of cases lead to liver failure
- disease sensitive to UVA and visible light
- light reflected off anything causes symptoms
erythropoietic protoporphyria
- burning, tingling, stinging pain and or itching when exposed to light occuring within minutes of sun exposure
- erythema, uticaria and or swelling when exposed to light
- waxy skin thickening over the knuckles and nose
- elliptical scars on the nose, cheeks and dorsum of hands
erythrpoietic proporphyria
investigations for erythopoietic protoporphyria?
- raised protoporphyrins in erythrocytes and stool
- urine not increased ^^
- check FBC some patients are anaemic
- RBC porphyrins
- Hb count
- biliary tract USS
treatment for erythopoietic protoporphyria?
- advice on sun exposure protection
- avoid iron
- anti-oxidants (e.g. oral beta carotene) - turns skin orange
- UVB phototherapy
- monitor for cholestasis and progressive liver damage
- give genetic counselling and 6 monthly LFTs
- rare autosomal dominant condition
- caused by a deficiency in the PBG deaminase enzyme
- causes acute neurovisceral attacks
- skin is unaffected
- risk of liver cancer and renal failure
- most common type of acute porphyria
acute intermittent porphyria
conditions to consider when diagnosing acute intermittent porphyria (extremely rare)
- acute abdomen
- mononeuritis multiplex
- guillian bare syndrome
- pysocoses
- nausea
- vomiting
- tachycardia
- low sodium
- neurological and psychiatric sign
- physiological upset
- 4 P’s
- painful abdomen
- polyneuropathy
- psychological disturbances
- port-wine coloured urine
acute intermittent porphyria
how is cytochrome P450 protein related to acute intermittent porphyria?
- production triggered by certain drugs
- containts haem
- breaks down many medications
presenting complaint
- little to see on skin surface but severe pain
- consider if patient isnt responding to “cellulitis” after antbiotic treatment
- out of proportion pain
- depth and extent may be greater than the appearance of the skin suggest
- presents after a hsitory of trauma (leg operation, insect bite, IV drug abuse)
- altered level of consciousness due to shock
- rapidly spreading and porrly demarcated purplish erythema
necrotising fascitis
treatment for necrotising fascitis?
- urgent surgical operation for debridement of necrotic tissue
- combination of IV broad spectrum antibiotics and contact microbiology immediately
classification of necrotizing type 1?
mixed anaerobes and coliforms (post abdominal surgery)
classification of necrotising fascitis type 2?
group A strep infection
when is the only scenario you should take a swab of a leg ulcer?
if signs of active infection suspected (e.g. cellulitis)
clinical definition of a leg ulcer?
ulcer between the kneww and ankle joint ongoing for more than 4 weeks
what blood vessel is involved in leg ulcers predominantly
80% are venous
what should a diagnosis of leg ulcer be based on?
- venous in nature
- arterial
- vasculitis
- malignant
- hydrostatic because no fluid is moving in the limb
what strain usually infects a leg ulcer?
- strep pyogens
- staph A
- or other anaerobes in diabetic patients
what condition?
- drug induced
- kaeratinocyte death
- results in epidermal detachment at the dermo-epidermal junction
- skin detaches in large necrotic sheets
- high mortality rate
toxic epidermal necrolysis
3 step plan for acute allergic reaction?
- chlorphenamine (dosed by age)
- treat asthma
- prednsilone
- if colapse give adrenaline
- seek urgent help if child does not imroive
difference between IgE mediated and non-IgE in allergy onset?
- IgE mediated = immediate onset
- non-IgE mediated = delayed onset
what is this?
psoriasis
what is the koebner phenomenon?
- psoriasis develops in area of skin trauma (e.g. in scratch mark or scar)
name some psoriasis types
what is auspitz sign?
- removal of surface scale
- reveals tiny bleeding points
- (dilated capillaries in elongated dermal papillae)
what are the management options for psoriasis?
- vitamin D analogues (calipotriol)
- coal tar
- dithranol
- steroid oitnments
- emollients (everyone should use)
what classifies as erythrodermic?
covers >90% of the body
what is mild acne?
- scattered papules
- pustules
- comedones
what is moderate acne?
- numerous papules
- pustules
- mild atrophic scarring
what is severe acne?
- cysts
- nodules
- significant scarring
what is this?
rhinophyma
persistence of nuceli in the keratin layer
parakeratosis
spongiosis
- oedema between karatinocytes
- characteristic of eczema
one appearance differnece between psoirasis and eczema
eczema is ill defined, psoirasis is well defined
is there a difference in dermatitis histologically?
no, all similar histologically
treatment of eczema?
- lots of emollients
- avoid irritatns incl. shower gels and soaps
- topical steroids
- treat infection
- phototherapy - mainly UVB
- systemic immunosuppressants
- (biologic agents)
important gene in eczema?
filaggrin
what causes pompholyx eczema?
an acute, sudden flare up of eczema
what are the mediators of itch?
name the causes of itch?
when may neuropathic itch occur?
after shingles
name some systemic disease associated with itch
haematological
paraneoplastic
liver and bile duct
psychogenic
kidney disease
thyroid disease
name line of management for itch?
- determine cause if possible
- treat the cause
- anti-itch treatments (usualy same as psoriasis)
- sedative anti-histamines
- emollients
- antidepressants
- phototherapy
- opiate antagonists, odanestron
