Physical Agents Flashcards
Second degree deep burns destroy deep follicular structures
True
Frostbite needs rapid rewarming
True
Phases of frostbite
1 - cooling
2. -thawing and rewarming
3 - extension of injury
4 - resolution
Pernio (chilblains) —> usually women and elderly, children in homes lacking central healing
True
Perniosis in children have a longer course
False - older individuals, younger pt improve spontaneously
Pernio - erythrocyanotic macules, papules, plaques in which distribution ?
Toes, fingers, ears, nose, heels
Histo of perniosis
Dermal oedema
Fluffy perivascular oedema
Superficial and deep lymphohistiocytic infiltrate with peri eccrine accentuation
Infiltrate is predominantly T lymphocytes
Associations of perniosis
Poor nutrition
Eating disorders
Haem malignancy
Autoimmune systemic disease (LE)
How does actinic prurigo differ from PMLE
Typically early age of onset with involvement of the dorsal nose , lips and conjunctivae
PMLE is immediate type hypersensitivity
False, delayed type
PMLE is mediated by T helper cells early then T suppressor cells at 72h
True
PMLE occurs in as little as 1 minute
False 10 min
Priming phenomenon also exists in chronic actinic dermatitis
False, PMLE with delay after exposure usually 6hr or more
Action spectrum of PMLE is UVA, UVB and rarely visible light
True
DDx PMLE
cutaneous lupus including tumid lupus Porphyria (when vesicles involved) Solar urticaria Photoexacerbated dermatoses Photo drug eruption Jessner’s lymphocytic infiltrate
Provocation testing not usually possible with PMLE
False - can be provoked by irradiating very small areas of skin monochromator
PMLE histo
Variable epidermal spongiosis
Superficial and deep perivascular and periappendegeal lymphohistiocytic dermal infiltrate, often with scattered eos and neuts
Significant dermal oedema
Actinic prurigo Perennial itchy papules and vesicles during acute flares
True
Actinic prurigo most commonly commences in childhood
True
Gene involved in actinic prurigo
HLA DRB1*0407
Actinic prurigo action spectrum
Usually both UVA and UVB (rarely UVA only)
Chronic actinic dermatitis broad spectrum but predominantly UVA
False,UVB
Chronic actinic dermatitis occurs seasonally
True
Chronic actinic dermatitis is less common in temperate climates
False - more common
Pseudolymphomatous changes occur in the setting of chronic actinic dermatitis
True
Actinic reticulohistiocytoma has pseudolymphomatous and nodular prurigo-like changes
True
Solar urticaria is induced by UVA, visible light and rarely UVB
True
10% of CAD resolve spontaneously in 6-7years
False 1-2 years
Solar urticaria usually exhibits hardening
False -= does not typically
Monochromator testing is particularly useful in solar urticaria
True as get urticarial reaction
Hydroa vacciniforme more common in males
True
Areas most commonly affected by hydroa vacciniforme
Cheeks, nose, ears, back of hands most commonly affected
Hydroa vacciniforme scars painlessly
False- painful
UVA wavelengths are implicated in hydroa vacciniforme
True
Need to assess immediate and delayed response with monochromator testing
True
Hydroa vacciniforme DDx
Hart up disease, EPP, Bullous LE, CTCL (HV-like CTCL reported in children)
Hydroa vacciniforme natural course
Usually improves and resolves by later teen years , spontaneous resolution in 60%, mean duration of 9 years
Hardening does not help hydroa vacciniforme
False - can do NBUVB in springtime
Complications of hydroa vacciniforme
Scarring, ocular complications, cartilage destruction
Hydroa vacciniforme aetiology unknown but relates to which virus?
EBV - virus can be found in inflammatory infiltrate in pt with HV in Asia.
HV like presentation of T cell lymphoma has been reported in children
True
Drugs causing photo onycholysis
Psoralens
Tetracyclines
PDT
Ciprofloxacin
What are the types of xanthomas
TV TED (PXP)
Tendinous Tuberous Eruptive Dyslipidaemic (includes plane, palmar and xanthelasma) Verruciform xanthoma
Eruptive xanthoma seen in setting of primary or secondary hypertriglyceridaemia
True
