VB Flashcards
What are the causes of non specific blisters?
BAAFI Burns Amyloidosis ABH False : cyst, mucocele, abscess Infection: herpes simplex, Zoster, coxsackie
What are the two broad categories for blisters?
Non specific
Specific
What are the causes of true blisters?
Primary
Secondary
Congenital
What are the causes of primary VB diseases?
Pepmphigus
Pepmphigoid
DH
Linear IgA disease
What are the causes if secondary VB?
EM, TEN, bullous diabeticorum,
Acute contact dermatitis
What are the congenital causes for VB diseases?
Epidermolysis bullosa: simplex junctional and dystrophic
Where are the sites of cleavage for blistering?
Corneal
Intra epidermal
Sub epidermal
What is pephigus?
Life threatening diseases which causes blistering of Mucocutaneous surfaces
What are the types of pemphigys?
Vulgaris which includes vegetans
Foliaceus which includes erythmatosus
Drug related: pencillin and rifampicin. Drugs that have sulphdryl groups
Para neoplastic: associated with underlying neoplasm known or occult
Which variant of pemphigus targets desmoglein 1 and 3 ?
Vulgaris
This is an AB mediated AI disease
The most severe form on pemphigus
Patient often starts with oral lesions and later develops skin lesions
Which variant of pemphigus targets desmoglein 1?
Foliaceus
The oral mucosa contains mainly which desmoglein?
3 hence why Vulgaris produces bad lesions in mourn as skin has 3 and 1
Antibodies against DSg3 will affect skin and mouth
Antibodies against DSG1 will affect mainly skin
T/F
Pemphigus is rare?
T
Which demographic is mainly affected by pemphigus?
Jewish and Italian
Female = Male
What is the aetiology of pemphigus?
HLA association however most cases are idiopathic including some triggers being medications, radiation, surgery, certain foods, emotional stress
Which version of pemphigus affects the whole width of epithelium?
Pemphigus Vulgaris
Which extra oral sites are affected in pemphigus?
Nose
Rectum
Scalp
What are the features of pemphigus?
Oral lesions: blisters which form erosion, desquammative gingivitis, and positive nikolsky sign
Skin lesion: these are common and large flaccid blisters form, eryhtmrstous apples and blisters, genital lesions, phaygrngea lesions
What is the pathology behind pemphigus?
Intercellular epithelial IgG against DSG 3 and 1and plakoglobin
Then forms intra epithelial bullae followed by acanthylosis which is intra epithelial splitting
What is the serology behind pemphigus?
Intercellular ABs to epithelium
What is the mortality of pemphigus if untreated?
30%
What investigations are carried out for diagnosis pemphigus?
Biopsy for histopathology and DIF
Bloods for IMF
Which our of DIF and IIF is more sensitive?
DIF
Which out of DIF and IIF tests for antibodies in serum?
IIF
Management of Pemphigus involves?
Biopsy: Histopathnand DIF Bloods: FBC, UE, Glucose, LFT, IMF Autoimmune profile: IIF TPMT for azothioprine G6PD: for dapsone
How can we manage pemphigus?
Acute control: topical and systemic steroids 40mg prednisalone daily
Manteance: topical and systemic steroids, Mycophenalte/AZTEC
IV Ig
Plasmapheresis
What are the two variants of pepmphigoid?
Mucous membrane and bullous
What are the features of MM pepmphigoid?
Late middl aged affecting females more than makes
Oral lesions: blood filled blisters which erode , desquammative gingivitis and possible nikolsky sign
Genital mucosa: blisters
Eyes: symblepheron
Skin lesions: rare
Usually a protracted course, lasts a long time
What is the pathology of MMP?
IgM/IgG and C3 to BMZ and this leads to sub epithelial bullae
Targets to BP1 and 2 and laminin 5
What are the features of Bullous pemphigoid?
Seen mainly in elderly and incidence is equal between males and females
Affects skin more than mucous membrane.
Due fined course which generally lasts for 5 years
Skin lesions: axilla, groin, flexures and abdomen
Oral lesions are rare and seen in 30% of people: affects gingiva , buccal and palatal mucosa
T/F
Bullous pemphigoid can occur secondary to drugs and UV light?
T
How do we investigate pemphigoid?
Same is pemphigus but consider referral for
How do we treat pemphigus?
Mild: topical steroids eg prednisalone and Immunosuppresants
Moderate: dapsone tetracycline and nicotinamide
Severe: dapsone
What are poor prognostic indicators for pemphigoid?
Circulating antibodies
High titre antibodies
Multi site involvement
Dermal binding sera
What is the demographics behind Dermatitis Herpetiformis?
It is rare and more common in males than females. Seen in 2nd - 3 rd decade
What is the pathology relating to DH?
IgA mediated autoantibody destruction at basement membrane zone
What is the aetiology of DH?
Associated with gluten sensitive enteropathy
Iodine allergy
HLAB8 and HLAD3
How does DH present?
Skin lesions: itchy rash on shoulders and pressure
Oral: palate, gingivae, buccal mucosa
It appears as erythmatous, purpuric, vesicular, ulcerative
Desquammative gingivitis and possible enamel Hypoplasia
What tests would you perform if you suspected DH?
Biopsy and direct IF
What would the biopsy for DH show?
IgA at BM zone
Immune complexes
AB to reticulin and endomycin
What does the direct immunofluorescence for DH show?
Granular IgA and C3 at tips of dermal papillae
How do you treat DH?
Dapsone
Supra pyridine
Gluten free diet
What is linear IgA disease?
This is a variant of DH where IgA is episodes along BM in a linear fashion
How does linear IgA disease present?
Oral vesicles and ulcers
Buttock scalp lesions
Treatment: mycophenalate mofetil
What is EM major?
Steven Johnson’s syndrome
What are the causes of Steven Johnson’s syndrome ?
MIID
Malignancy
Infection: 30% associated with herpes, HIV and mycoplasma eg M pneumoniae
Drugs: PHABSS penicillin, hydantoins, anti malarial, barbiturates, salicylates, sulphonamide
What are the features of EM?
Seen in young (male) adolescents
Swollen blood Staines crusted lips
In the mouth see macular rash, blisters and ulcers at anterior of mouth
Can get eye lesions too
How often does EM attack?
10-14 days
Twice a year
For three years
What are the signs of SJS?
Eyes: conjunctivtis, dry eyes, symblepheron
Stomatitis
Genital lesions: balanitis, urethritis, vulval ulceration
Skin: target lesions
Lung and renal involvement
What is TEN?
Childhood variant of EM
How do you diagnose EM?
Clinically
Histopath
Virology since need to compare with herpetic gingivo
Direct IMF: basement membrane shows C3 and fibrin at Basement membrane
Perivascular: c3 fine IGM
How do treat EM?
Biopsy Ophthalmology Topical and systemic steroids Immunosuppressant eg azothioprine Antiviral
What are the complications of MMP?
Skin: blistering and ulceration
Genital: blistering, ulceration adm scarring
Pharyngeal involvement: blistering,ulcer and scar. Strictures can lead to dysphgia
Oral: blistering and periodontal tissue loss due to inability to maintains OH
Eyes: entropian: inversion of eyelash, blepharitis: sclera inflam and irrataation
