Dermatology Secondary Care Flashcards
What is bullous pemphigoid?
A chronic, autoimmune, subepidermal blistering skin disorder.
How does bullous pemphigoid differ from pemphigus?
Pemphigus - intra-epidermal blistering, painful not pruritic
Pemphigoid - sub epidermal blistering, painful and pruritic
What is the median age of onset in bullous pemphigoid?
80 years
What is the autoantigen in bullous pemphigoid and what is its function?
Type XVII collagen (COL17)
in the basement membrane
What are three risk factors for bullous pemphigoid?
Lichen planus/psoriasis
NSAIDS/furosemide/captoptil
Radiotherapy
How does bullous pemphigoid present?
Urticarial/erythematous rash on limbs precedes blisters - urticarial prodrome
Blisters/bullae occur in skin flexures, are fluid filled
Post inflammatory hyperpigmentation/milia
Patient is otherwise well
How is bullous pemphigoid diagnosed?
Skin biopsy followed by direct immunofluorescence (DIF)
Deposit of IgG and C3 on the epidermis side of the dermal/epidermal junction
What is seen on the histology of a bullous pemphigoid patient?
Subepidermal blister with fibrin and inflammatory infiltrate and eosinophilic predominance. Intact epidermis
What is the management of bullous pemphigoid?
Urgent referral to secondary care/admission
Dermovate cream
If more severe, PO prednisolone
If systemic steroid treatment lasts more than one month, what is given?
PPI and bisphosphonates
What is a complication of bullous pemphigoid?
Secondary infection and sepsis
What is pemphigus?
A group of autoimmune disorders where there is blistering of the skin and/or mucosal surfaces.
What is the pathophysiology of pemphigus?
Circulating IgG autoantibodies bind to antigens (desmosomes) on the surface of keratinocytes leading to acantholysis (keratinocytes separate from each other)
What are some risk factors for pemphigus?
Female
Older age
Asian and Ashkenazi Jews
Pregnancy and stress
What are the main three subtypes of pemphigus?
Pemphigus vulgaris
Pemphigus foliaceus
Paraneoplastic pemphigus
How does the skin symptoms of pemphigus present?
Blisters on normal or erythematous skin and are flaccid
Affected skin is painful but rarely pruritic
Intertriginous areas - granulation and crusting
What are the other symptoms of pemphigus?
Nail changes
Burst gingival, buccal, and palatine bullae that are painful and slow healing.
Conjunctivae, oesophagus, and genitalia
How is pemphigus definitively diagnosed?
Skin biopsy from the edge of a blister, histology and DIF/IDIF
ELISAs for DSG1 and DSG3 in serum
What are the three phases of management of pemphigus?
Control, consolidation, maintenance.
What are the treatment options in the control phase of pemphigus management?
PO prednisolone
2nd line: plasmaphresis 3xw w/ azathioprine or cyclophosphamide
3rd line: IVIG
Describe the consolidation and maintenance phases of management of pemphigus.
Step down regime and tapering after 80% lesions have healed
Steroid sparing agents sometimes used to further reduce dose
What are the complications of pemphigus?
Secondary infection
Effects of corticosteroids
Malignancy immunosuppression
Give four differences between pemphigus and bullous pemphigoid
Pemphigus: younger, flaccid epidermal bullae, not pruritic
Pemphigoid: Older, tense subepidermal bullae, pruritic
What is lichen planus?
A pruritic, popular eruption characterized by its violaceous colour and polygonal shape.
What are the five Ps of lichen planus?
Purple Pruritic Polyangular Planus (flat-topped) Papules
Where is the rash of lichen planus found?
Flexor surfaces of extremities, upper>lower
Genitalia
Mucous membranes
What are some characteristic signs of lichen planus?
Lacy white lesions on mucous membranes
Intensely itchy 2-5mm red/violet shiny flat-topped papular with Wickham’s Striae
What occurs when papules clear in lichen planus?
They are replaced by brown discolouration
What are the nail and scalp changes seen in lichen planus?
Longitudinal ridges
Scarring alopecia
What are the potential causes of lichen planus?
T-cell mediated
Kobner’s phenomenon
RF: hepatitis C, PBC, female
What are the variations of lichen sclerosis?
Hypertrophic Atrophic Erosive/ulcerative Follicular Vesicular/bullous
What is seen on skin biopsy and histology in lichen planus?
Saw tooth pattern of epidermal hyperplasia and vacuolar alteration of the epidermis
T lymphohistioctic infiltration
Reduced melanocytes - Wickham’s striae
Globular deposits of IgM
What is the treatment of lichen planus?
Symptomatic itch treatment - potent corticosteroids and topical antifungals
Psoralen and PUVA radiation treatment
Systemic steroids
What is lichen simplex chronicus?
Localized area of skin becomes thickened and leathery due to chronic rubbing
What is the treatment of lichen simplex chronicus?
Superpotent corticosteroid ointment
Less potent if genital skin
50% of melanomas result following which mutation?
BRAF V600 on C7q34
What are five risk factors for malignant melanoma?
Previous history of melanoma More than 100 naevi Sun exposure Skin type 1 or 2 Solar keratoses