Flashcards in Inflammatory skin diseases Deck (141):
What are the 4 types of inflammatory skin diseases and what do they look like histologically?
Psoriaform = elongated rete ridges
Spongiotic = intra-epidermal oedema (eczema)
Lichenoid = damaged basement membranes (lichen planus/Lupus)
Vestibulobullous = blistering
What are the 3 types of vestibulobullous inflammatory skin disease?
What is the prevelance of psoriasis?
What are the 9 environmental triggers of psoriasis?
What is the mean age of onset of psoriasis?
What condition is particularly associated with psoriasis?
What is the genetic risk of inheritance of psoriasis?
1 parent = 25%
2 parents = 60%
__% of psoriasis patients have a +ve family history
Describe the general pathology of psoriasis
Keratinocytes under stress triggers wrongly continuing late phase would healing response
What are the 4 main histological features of psoriasis?
Chronic inflammation altered tissue structure
Elongation of rete ridges
What are the 9 types/patterns of psoraisis?
What are 4 discussion points for a diagnostic consultation of psoriasis?
Social/psychological problems are common
What is the primary systemic effect of psoriasis?
increased cardiovascular risk
What 3 measurements should be monitored in psoriasis for CVD?
Glucose for DM
What are the 6 main co-morbidities associated with psoriasis?
What are 4 features of generalised pustular psoriasis?
Patient is systemically unwell
Sheets of small yellowish pustules
Develops on erythematous background
Give 4 features of the lesions of chronic plaque psoriasis
Well-defined, disc shaped lesions
Covered in waxy/white scale
Auspitz sign (bleeds after scale is removed)
What are the 6 areas commonly affected by chronic plaque psoriasis?
What are the 4 nail changes seen in psoriasis?
What are the 2 differentials for chronic plaque psoriasis?
Psoriatic drug reaction
Hypertrophic lichen planus
What are the 4 main features of Guttate psoriasis?
Acute, symmetrical rain drop lesions
Itchy and uncomfortable
Can have a scaly surface
What is the primary location of Guttate psoriasis?
What normally preceeds Guttate psoriasis?
Strep throat infection
What are the 2 consequences of Guttate psoriasis?
Goes on to chronic plaque psoriasis
What is the differential diagnosis for Guttate psoriasis?
What is the age range commonly affected by Guttate psoriasis?
Teens and young adults
What are the 3 main locations for flexural psoriasis?
What is the common age range for flexural psoriasis?
What do the plaques look like in flexural psoriasis?
What is a differential diagnosis for flexural psoriasis?
What is psoriatic nail changes associated with?
What is the differential diagnosis for psoriatic nail changes, and how can they be distinguished?
Fungal nail infection
Send clippings for mycology
Describe palmoplantar pustular psoriasis
Yellow/brown sterile pustules on palms or soles
What is napkin psoriasis?
Well-defined eruption in nappy area of infants
__% of patients with psoriatic skin changes are affected by psoriatic arthropathy
What are the 3 pieces of general advice given to those with psoraisis in terms of management?
Avoid excess alcohol
Maintain an optimum weight
What are the 6 possible topical theraputics that can be used in psoriasis?
Vitamin D analogues
What are the 3 therapies used for refractory psoraisis?
Phototherapy (UVB then PUVA)
Immune modulation (targeted biologics)
What is the main immunosuppressant used in psoriasis?
What is an example of a vitamin D analogue?
What are the 2 disadvantages of dithranol?
Can be an irritant
Stains normal skin
What must you be careful about with topical steroids and psoriasis?
What are the 4 treatments used for scalp psoriasis?
Greasy ointment (to soften scale)
Steroids in alcohol base or shampoo
Vitamin D analogues
What are the 2 main options for management of flexural psoriasis?
Mild/moderate topical steroids
What are the 2 effects of coal-tar in psoriasis?
What are the 2 advantages of vitamin D analogues?
No smell and does not stain clothing
What is the max dosage of vitamin D?
What is the consequence of excess vitamin D analogue usage?
Systemic absorbtion causing hypercalcaemia
NICE stages of management of chronic plaque psoriasis
1 = potent corticosteroid (1/d) and vitamin D analogue (1/d) for 4 weeks
2 = vitamin D analogue twice daily if no improvement after 8 weeks
3 = Either potent corticosteroids twice daily (up to 4 months)
Or coal tar preparation 1-2/day
If no improvement after 8-12 weeks
+ regular emollients
+Short-acting dithranol if needed
What is the initial stage of chronic plaque psoriasis management?
Potent corticosteroid once/day and vitamin D analogue once/day for 4 weeks
What is the 2nd stage of chronic plaque psoriasis management if there is no improvement after 8 weeks of stage 1?
Increase vitamin D analogue to 2/day
What is the 3rd stage of chronic plaque psoriasis management if there is no improvement after 8-12 weeks?
Either give potent corticosteroid 2/day (for up to 4 months)
Coal tar preparation 1-2/day
What should always be given to patients with psoriasis, regardless of their stage in treatment?
What are the 2 histological hallmarks of dermatitis?
Inflammatory cell infiltrate
What is the characteristic symptom of dermatitis?
What are the 4 main features of dermatitis?
What are the 4 features of acute phase eczema?
What are the features of chronic eczema due to?
What are the 3 main features of chronic phase eczema?
What type of hypersensitivity is contact allergy?
Delayed type 4 hypersensitivity
What is the cause of contact irritant dermatitis?
Chemical trauma (from soap or water)
What is the cause of atopic dermatitis?
Genetic and environmental factors resulting in inflammation
What type of hypersensitivity reaction is drug-induced dermatitis?
Either a type1 or type 4
What is present in a biopsy of drug-induced dermatitis?
What is the cause of lichen simplex?
Physical trauma to the skin due to scratching
What is the cause of stasis dermatitis?
Physical trauma to the skin via hydrostatic pressure and extravasation of RBCs
Atopic dermatitis is due to impaired ____ ___ ___
Skin barrier function
What mutation can be found in some eczema patients, and what is it associated with?
Filaggrin gene mutation
= severe/earlier onset of disease
What is the normal function of filaggrin?
Breakdown on the keratin layer, with the products helping to bind water to the keratin layer (=> moisturising)
What is the effect of a mutated filaggrin gene in eczema?
Decreased AMP => dryness and increased microbe penetration to skin
What are the 2 main consequences of the defective skin barrier in eczema?
Allows access/sensitisation to allergens
Promotes colonisation by micro-organisms
What are the 5 main components of the immune system involved in the development of atopic eczema?
Which 2 interleukins are associated with eczema?
IL-4 and IL-13
Describe the non-lesional skin in eczema?
What is the classical distribution of eczema?
What is the distribution of eczema in infants?
Cheeks and extensor surfaces
What is the general condition of the skin in eczema?
What is the diagnostic criteria for eczema?
Itching + 3 or more of:
Visible flexural rash (cheeks and extensors in infants)
History of flexural rash
Personal history of atopy (1st-degree relative if <4y/o)
Generally dry skin
Onset before 2 y/o
What are the 6 possible treatments for eczema?
Plenty of emollients (250g/w)
Avoid irritants (incl. shower gels and soaps)
What are the 2 complications of ezcema?
Staph aureus infection
What is the characteristic feature of staph aureus skin infection?
Why are atopic children much more likely to get a staph aureus infection?
They have a much higher carriage rate
What is the cause of eczema herpeticum?
Infection of eczematous rash with herpes simplex virus
What does eczema herpeticum look like?
Monomorphic, punched out lesions
What is the difference between discoid eczema and normal eczema?
Discoid = well defined (normal = ill defined)
How can you distinguish between discoid eczema and psoriasis?
Discoid eczema = flat
(psoriasis = plaque => raised)
What is the common complication of discoid eczema?
Staph aureus infection
What is photosensitive eczema also known as?
Chronic actinic dermatitis
What is a distinctive feature of photosensitive eczema?
Cut-off of rash at clothing lines
What are the 3 causes of varicose eczema?
Red cell extravsation
What is the medical term for cradle cap?
What are the 4 main causes of erythroderma?
Why can erythroderma be so serious?
Causes electrolyte imbalance
Give 2 examples of lichenoid disorders with a marked vacuolar interface changes
Topical epidermal necrolysis
What is the prevelance of lichen planus?
What are the 5 histological features of lichen planus?
Irregular saw tooth acanthosis
Band-like upper dermal infiltrate of lymphocytes
Basal damage with formation of cytoid bodies
Give 2 descriptions of the lesions of lichen planus
Itchy, flat topped violaceous papules
What are the 2 extra-dermal manifestations of lichen planus?
White reticular pattern on buccal mucosa
What are the 4 locations of a lichen planus rash?
How long does lichen planus last before burning out?
What is the treatment of lichen planus based on?
What is the management for lichen planus?
Potent topical steroids
What should be given to treat very extensive lichen planus?
What is pompholyx eczema?
Sudden onset of itchy, spongiotic vesicles
What are immunobullous disorders?
Diseases that have blisters as their primary feature
What is the cause of immunobullous conditions?
Autoimmune damage to adhesion points in the epidermis/dermis
What is the cause of pemphigus?
Autoimmune damage to the desmosomes
What are the 2 types of pemphigus?
What would make a pemphigus disease very severe/fatal
Affecting the resp or GI tract
What histological feature is common to all pemphigus?
Anantholysis - lysis of intercellular adhesion points
How do you differentiate between pemphigus vulgaris and pemphigoid?
What is Nikolsky's sign +ve?
If by rubbing the epidermis, the top layers come off
What is the cause of 80% of pemphigus?
What is the cause of pemphigus vulgaris?
Autoimmune destruction of desmoglein 3 via IgG auto-antibodies
What is the end result of the pathogenesis of pemphigus vulgaris?
What is the presentation of pemphigus vulgaris?
Flaccid, fluid-filled blisters that form shallow erosions
What are the 5 locations most likely to be affected by pemphigus vulgaris?
What symptom often accompanies the blisters in pemphigus vulgaris?
Pain, but not itching
What is left behind when pemphigus vulgaris blisters rupture?
Shallow eropsions - likely to get infected
What is seen on biopsy of pemphigus vulgaris?
What is the treatment for pemphigus vulgaris?
Steroids and immunosuppressant
What is the prognosis/natural progression of pemphigus vulgaris?
Chronic self-limiting to 3-6months but high mortality if left untreated
Where is the blister in Bullous pemphigoid?
Is acanthosis seen in pemphigoid?
What histological sign is pathognomonic of pemphigus?
What group of people is normally affected by bullous pemphigoid?
What is the cause of bullous pemphigoid?
IgG antibodies react with an antigen of the hemidesmosomes (anchor basal cells to the basement membrane) => entire epidermis detaches from basement membrane
What is the presentation of bullous pemphigoid?
Tense blisters that can be preceeded by itchy, erythematous plaques/papules
Describe the distribution of bullous pemphigoid
Localised to one area
OR over trunk and limbs
How are patients when they have pemphigoid?
Will pemphigoid affect mucous membranes?
What is seen on biopsy of bullous penphigoid?
Linear IgG and complement deposition around the basement membrane
Bullous pemphigoid is Nikosky's sign ____
Describe the natural progression of pemphigoid
Self-limiting over months to years with lower mortality than pemphigus
What is the mainstay of bullous pemphigoid amangement?
What can be used to manage bullous pemphigoid in addition to oral steroids?
What do 90% of dermatitis herpetiformis patients ahve?
What HLA is associated with dermitis herpetiformis?
What is the histological hallmark of dermatitis herpetiformis?
Papillary derma microabscesses
What is the cause of dermatitis herpetiformis?
IgA antibodies cross react with connective tissue proteins in the dermal papillae