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1.1 Dermatology > Inflammatory skin diseases > Flashcards

Flashcards in Inflammatory skin diseases Deck (141)
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1
Q

What are the 4 types of inflammatory skin diseases and what do they look like histologically?

A
Psoriaform = elongated rete ridges
Spongiotic = intra-epidermal oedema (eczema)
Lichenoid = damaged basement membranes (lichen planus/Lupus)
Vestibulobullous = blistering
2
Q

What are the 3 types of vestibulobullous inflammatory skin disease?

A

Pemphigus
Pemphigoid
Dermatitis herpetiformis

3
Q

What is the prevelance of psoriasis?

A

2-3%

4
Q

What are the 9 environmental triggers of psoriasis?

A
Trauma
Infection
NSAIDs
Beta-blockers
Lithium
Alcohol
Sunlight (10%)
Psychological stress
5
Q

What is the mean age of onset of psoriasis?

A

28 y/o

6
Q

What condition is particularly associated with psoriasis?

A

IBD (Crohn’s>UC)

7
Q

What is the genetic risk of inheritance of psoriasis?

A

1 parent = 25%

2 parents = 60%

8
Q

__% of psoriasis patients have a +ve family history

A

35%

9
Q

Describe the general pathology of psoriasis

A

Keratinocytes under stress triggers wrongly continuing late phase would healing response

10
Q

What are the 4 main histological features of psoriasis?

A

Chronic inflammation altered tissue structure
Hyperkeratosis
Elongation of rete ridges
Munro-micro-abscesses (neutrophils)

11
Q

What are the 9 types/patterns of psoraisis?

A
Erythroderma
Generalised pustular
Plaque (m/c)
Scalp psoriasis
Guttate
Flexural
Nail
Palmoplantar pustulosis
Napkin psoriasis
12
Q

What are 4 discussion points for a diagnostic consultation of psoriasis?

A

Explain/decide management
Chronic condition
Not infectious
Social/psychological problems are common

13
Q

What is the primary systemic effect of psoriasis?

A

increased cardiovascular risk

14
Q

What 3 measurements should be monitored in psoriasis for CVD?

A

BP
Lipids
Glucose for DM

15
Q

What are the 6 main co-morbidities associated with psoriasis?

A
Psoriatic arthritis
Metabolic syndrome
Crohn's disease
Cancer
Depression
Uveitis
16
Q

What are 4 features of generalised pustular psoriasis?

A

Patient is systemically unwell
Sheets of small yellowish pustules
Develops on erythematous background
Spreads rapidly

17
Q

Give 4 features of the lesions of chronic plaque psoriasis

A

Well-defined, disc shaped lesions
Red
Covered in waxy/white scale
Auspitz sign (bleeds after scale is removed)

18
Q

What are the 6 areas commonly affected by chronic plaque psoriasis?

A
Knees
Elbows
Scalp
Hair margin
Sacrum
Extensor surfaces
19
Q

What are the 4 nail changes seen in psoriasis?

A

Pitting
Onchyolysis
Dystrophy
Subungal hyperkeratosis

20
Q

What are the 2 differentials for chronic plaque psoriasis?

A

Psoriatic drug reaction

Hypertrophic lichen planus

21
Q

What are the 4 main features of Guttate psoriasis?

A

Acute, symmetrical rain drop lesions
Itchy and uncomfortable
Salmon-pink papules
Can have a scaly surface

22
Q

What is the primary location of Guttate psoriasis?

A

Trunk/limbs

23
Q

What normally preceeds Guttate psoriasis?

A

Strep throat infection

Viral infection

24
Q

What are the 2 consequences of Guttate psoriasis?

A

Heals completely

Goes on to chronic plaque psoriasis

25
Q

What is the differential diagnosis for Guttate psoriasis?

A

Pityriasis roasea

26
Q

What is the age range commonly affected by Guttate psoriasis?

A

Teens and young adults

27
Q

What are the 3 main locations for flexural psoriasis?

A

Armpits
Sub-mammary
Natal cleft

28
Q

What is the common age range for flexural psoriasis?

A

Elderly

29
Q

What do the plaques look like in flexural psoriasis?

A

Smooth/glazed

30
Q

What is a differential diagnosis for flexural psoriasis?

A

Flexural candiasis

31
Q

What is psoriatic nail changes associated with?

A

Psoriatic arthropathy

32
Q

What is the differential diagnosis for psoriatic nail changes, and how can they be distinguished?

A

Fungal nail infection

Send clippings for mycology

33
Q

Describe palmoplantar pustular psoriasis

A

Yellow/brown sterile pustules on palms or soles

34
Q

What is napkin psoriasis?

A

Well-defined eruption in nappy area of infants

35
Q

__% of patients with psoriatic skin changes are affected by psoriatic arthropathy

A

40%

36
Q

What are the 3 pieces of general advice given to those with psoraisis in terms of management?

A

Stop smoking
Avoid excess alcohol
Maintain an optimum weight

37
Q

What are the 6 possible topical theraputics that can be used in psoriasis?

A
Emollients
Coal tar
Vitamin D analogues
Dithranol
Salicylic acid
Topical steroids
38
Q

What are the 3 therapies used for refractory psoraisis?

A

Phototherapy (UVB then PUVA)
Immunosuppression (methotrexate)
Immune modulation (targeted biologics)

39
Q

What is the main immunosuppressant used in psoriasis?

A

Methotrexate

40
Q

What is an example of a vitamin D analogue?

A

Calcipotriol

41
Q

What are the 2 disadvantages of dithranol?

A

Can be an irritant

Stains normal skin

42
Q

What must you be careful about with topical steroids and psoriasis?

A

Rebound psoriasis

43
Q

What are the 4 treatments used for scalp psoriasis?

A

Greasy ointment (to soften scale)
Tar shampoo
Steroids in alcohol base or shampoo
Vitamin D analogues

44
Q

What are the 2 main options for management of flexural psoriasis?

A

Mild/moderate topical steroids

Calcineurin inhibitors

45
Q

What are the 2 effects of coal-tar in psoriasis?

A

Anti-inflammatory

Anti-scaling

46
Q

What are the 2 advantages of vitamin D analogues?

A

No smell and does not stain clothing

47
Q

What is the max dosage of vitamin D?

A

100g/week

48
Q

What is the consequence of excess vitamin D analogue usage?

A

Systemic absorbtion causing hypercalcaemia

49
Q

NICE stages of management of chronic plaque psoriasis

A

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

50
Q

What is the initial stage of chronic plaque psoriasis management?

A

Potent corticosteroid once/day and vitamin D analogue once/day for 4 weeks

51
Q

What is the 2nd stage of chronic plaque psoriasis management if there is no improvement after 8 weeks of stage 1?

A

Increase vitamin D analogue to 2/day

52
Q

What is the 3rd stage of chronic plaque psoriasis management if there is no improvement after 8-12 weeks?

A

Either give potent corticosteroid 2/day (for up to 4 months)
OR
Coal tar preparation 1-2/day

53
Q

What should always be given to patients with psoriasis, regardless of their stage in treatment?

A

Regular emollients

54
Q

What are the 2 histological hallmarks of dermatitis?

A

Spongiosis

Inflammatory cell infiltrate

55
Q

What is the characteristic symptom of dermatitis?

A

Intense itch

56
Q

What are the 4 main features of dermatitis?

A

Itchy
Ill-defined
Erythematous
Scaly

57
Q

What are the 4 features of acute phase eczema?

A

Papulovesicular
Erythematous
Oedema/spongiosis
Ooze/scaling/crusting

58
Q

What are the features of chronic eczema due to?

A

Chronic itching

59
Q

What are the 3 main features of chronic phase eczema?

A

Thickening (lichenification)
Elevated plaques
Increased scaling

60
Q

What type of hypersensitivity is contact allergy?

A

Delayed type 4 hypersensitivity

61
Q

What is the cause of contact irritant dermatitis?

A

Chemical trauma (from soap or water)

62
Q

What is the cause of atopic dermatitis?

A

Genetic and environmental factors resulting in inflammation

63
Q

What type of hypersensitivity reaction is drug-induced dermatitis?

A

Either a type1 or type 4

64
Q

What is present in a biopsy of drug-induced dermatitis?

A

Eosinophils

65
Q

What is the cause of lichen simplex?

A

Physical trauma to the skin due to scratching

66
Q

What is the cause of stasis dermatitis?

A

Physical trauma to the skin via hydrostatic pressure and extravasation of RBCs

67
Q

Atopic dermatitis is due to impaired ____ ___ ___

A

Skin barrier function

68
Q

What mutation can be found in some eczema patients, and what is it associated with?

A

Filaggrin gene mutation

= severe/earlier onset of disease

69
Q

What is the normal function of filaggrin?

A

Breakdown on the keratin layer, with the products helping to bind water to the keratin layer (=> moisturising)

70
Q

What is the effect of a mutated filaggrin gene in eczema?

A

Decreased AMP => dryness and increased microbe penetration to skin

71
Q

What are the 2 main consequences of the defective skin barrier in eczema?

A

Allows access/sensitisation to allergens

Promotes colonisation by micro-organisms

72
Q

What are the 5 main components of the immune system involved in the development of atopic eczema?

A
Th2 cells
Dendritic cells
Keratinocytes
Macrophages
Mast cells
73
Q

Which 2 interleukins are associated with eczema?

A

IL-4 and IL-13

74
Q

Describe the non-lesional skin in eczema?

A

Not normal

75
Q

What is the classical distribution of eczema?

A

Flexural surfaces

76
Q

What is the distribution of eczema in infants?

A

Cheeks and extensor surfaces

77
Q

What is the general condition of the skin in eczema?

A

Dry

78
Q

What is the diagnostic criteria for eczema?

A

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

79
Q

What are the 6 possible treatments for eczema?

A
Plenty of emollients (250g/w)
Avoid irritants (incl. shower gels and soaps)
Topical steroids
Treating infections
Phototherapy (UVB)
Systemic immunosuppressants
80
Q

What are the 2 complications of ezcema?

A

Staph aureus infection

Eczema herpeticum

81
Q

What is the characteristic feature of staph aureus skin infection?

A

Golden crust

82
Q

Why are atopic children much more likely to get a staph aureus infection?

A

They have a much higher carriage rate

83
Q

What is the cause of eczema herpeticum?

A

Infection of eczematous rash with herpes simplex virus

84
Q

What does eczema herpeticum look like?

A

Monomorphic, punched out lesions

85
Q

What is the difference between discoid eczema and normal eczema?

A

Discoid = well defined (normal = ill defined)

86
Q

How can you distinguish between discoid eczema and psoriasis?

A

Discoid eczema = flat

psoriasis = plaque => raised

87
Q

What is the common complication of discoid eczema?

A

Staph aureus infection

88
Q

What is photosensitive eczema also known as?

A

Chronic actinic dermatitis

89
Q

What is a distinctive feature of photosensitive eczema?

A

Cut-off of rash at clothing lines

90
Q

What are the 3 causes of varicose eczema?

A

Hydrostatic pressure
Oedema
Red cell extravsation

91
Q

What is the medical term for cradle cap?

A

Seborrhoeic dermatitis

92
Q

What are the 4 main causes of erythroderma?

A

Drugs
Lymphedemas
Psoriasis
Eczema

93
Q

Why can erythroderma be so serious?

A

Causes electrolyte imbalance

94
Q

Give 2 examples of lichenoid disorders with a marked vacuolar interface changes

A

Erythema multiform

Topical epidermal necrolysis

95
Q

What is the prevelance of lichen planus?

A

0.5%

96
Q

What are the 5 histological features of lichen planus?

A

Irregular saw tooth acanthosis
Hypergranulation
Orthohyperkeratosis
Band-like upper dermal infiltrate of lymphocytes
Basal damage with formation of cytoid bodies

97
Q

Give 2 descriptions of the lesions of lichen planus

A

Itchy, flat topped violaceous papules

Wickham’s striae

98
Q

What are the 2 extra-dermal manifestations of lichen planus?

A

White reticular pattern on buccal mucosa

Nail ridges

99
Q

What are the 4 locations of a lichen planus rash?

A

Volar wrist
Forearms
Shins
Ankles

100
Q

How long does lichen planus last before burning out?

A

12-18 months

101
Q

What is the treatment of lichen planus based on?

A

Symptoms

102
Q

What is the management for lichen planus?

A

Potent topical steroids

103
Q

What should be given to treat very extensive lichen planus?

A

Oral steroids

104
Q

What is pompholyx eczema?

A

Sudden onset of itchy, spongiotic vesicles

105
Q

What are immunobullous disorders?

A

Diseases that have blisters as their primary feature

106
Q

What is the cause of immunobullous conditions?

A

Autoimmune damage to adhesion points in the epidermis/dermis

107
Q

What is the cause of pemphigus?

A

Autoimmune damage to the desmosomes

108
Q

What are the 2 types of pemphigus?

A

Pemphigus Vulgaris

Bullous pemphigoid

109
Q

What would make a pemphigus disease very severe/fatal

A

Affecting the resp or GI tract

110
Q

What histological feature is common to all pemphigus?

A

Anantholysis - lysis of intercellular adhesion points

111
Q

How do you differentiate between pemphigus vulgaris and pemphigoid?

A

Nikolsky’s sign

112
Q

What is Nikolsky’s sign +ve?

A

If by rubbing the epidermis, the top layers come off

113
Q

What is the cause of 80% of pemphigus?

A

Pemphigus vulgaris

114
Q

What is the cause of pemphigus vulgaris?

A

Autoimmune destruction of desmoglein 3 via IgG auto-antibodies

115
Q

What is the end result of the pathogenesis of pemphigus vulgaris?

A

Acantholysis

116
Q

What is the presentation of pemphigus vulgaris?

A

Flaccid, fluid-filled blisters that form shallow erosions

117
Q

What are the 5 locations most likely to be affected by pemphigus vulgaris?

A
Trunk
Face
Groin
Axillae
Scalp
118
Q

What symptom often accompanies the blisters in pemphigus vulgaris?

A

Pain, but not itching

119
Q

What is left behind when pemphigus vulgaris blisters rupture?

A

Shallow eropsions - likely to get infected

120
Q

What is seen on biopsy of pemphigus vulgaris?

A

Intra-epidermal IgG

121
Q

What is the treatment for pemphigus vulgaris?

A

Steroids and immunosuppressant

122
Q

What is the prognosis/natural progression of pemphigus vulgaris?

A

Chronic self-limiting to 3-6months but high mortality if left untreated

123
Q

Where is the blister in Bullous pemphigoid?

A

Sub-epidermal

124
Q

Is acanthosis seen in pemphigoid?

A

No

125
Q

What histological sign is pathognomonic of pemphigus?

A

Tombstones

126
Q

What group of people is normally affected by bullous pemphigoid?

A

Elderly patients

127
Q

What is the cause of bullous pemphigoid?

A

IgG antibodies react with an antigen of the hemidesmosomes (anchor basal cells to the basement membrane) => entire epidermis detaches from basement membrane

128
Q

What is the presentation of bullous pemphigoid?

A

Tense blisters that can be preceeded by itchy, erythematous plaques/papules

129
Q

Describe the distribution of bullous pemphigoid

A

Localised to one area

OR over trunk and limbs

130
Q

How are patients when they have pemphigoid?

A

Generally well

131
Q

Will pemphigoid affect mucous membranes?

A

No

132
Q

What is seen on biopsy of bullous penphigoid?

A

Linear IgG and complement deposition around the basement membrane

133
Q

Bullous pemphigoid is Nikosky’s sign ____

A

Negative

134
Q

Describe the natural progression of pemphigoid

A

Self-limiting over months to years with lower mortality than pemphigus

135
Q

What is the mainstay of bullous pemphigoid amangement?

A

Oral corticosteroids

136
Q

What can be used to manage bullous pemphigoid in addition to oral steroids?

A

Topical corticosteroids
Immunosuppressants
Antibiotics

137
Q

What do 90% of dermatitis herpetiformis patients ahve?

A

Coeliac disease

138
Q

What HLA is associated with dermitis herpetiformis?

A

HLA-DQ2

139
Q

What is the histological hallmark of dermatitis herpetiformis?

A

Papillary derma microabscesses

140
Q

What is the cause of dermatitis herpetiformis?

A

IgA antibodies cross react with connective tissue proteins in the dermal papillae

141
Q

Describe the presentation of dermatitis herpetiformis?

A

Intensely itchy, symmetrical lesions across the elbows, knees and buttocks