Autoimmunity, Drug Reactions And Vasculitis

Question 1

Cutaneous drug eruptions

Answer 1

Majority are benign

Many drugs are implicated
- most common = amoxicillin, sulfa drugs, anticonvulsants and anti-HIV medications

Most common form of rash = morbilliform (92%)
- can also be urticarial (8%)

Populations at highest risk

• elderly
• autoimmune patients
• stem-cell transplant patients
• EBV/HIV infections with (CD4 <200)

Question 2

Drugs associated with erythema multiforme rashes

Answer 2

Target-like lesions which are mainly on the tensor aspects of limbs

• often appear bullae
• if on mucosa and systemic illness symptoms = SJ syndrome

Most commonly caused by:

• sulphonamides
• barbiturates
• lamotrigine
• phenyl-butazone

Question 3

Fixed drug eruptions

Answer 3

Are round erythematous/purple plaques that can be bullous
- most commonly found on genitalia or injection site

Most common agents
- paracetamol, TMP-SMX, NSAIDs/aspirin, systemic antifungal agents

Question 4

Red man syndrome is most heavily tied to what medication?

Answer 4

Vancomycin

Question 5

Small blood vessel vasculitis includes

Answer 5

Blood vessels affected are all <50um in thickness

HSP

Urticarial vasculitis (UV)

Cryoglobulinemic Vasculitis (CV)

Cutaneous leukocytoclastic angitits (CSVV

Question 6

Medium sized blood vessel vasculitis include what?

Answer 6

All affect blood vessels 50-150um in size

Poly arteritis nodosa (PAN)

Kawasaki disease (KD)

Question 7

Mixed vessel vasculitis includes what?

Answer 7

Variable vessel affects

Microscopic polyangiitis (MPA)

Wegener granulomatosis (WG)

Churg-Strauss syndrome (CSS)

Question 8

Small vessel leuckocytoclastic vasculitis

Answer 8

is the most common type of vasculitis encountered

Dermatological manifestations:

• purpuric lesions
• erythematous papules/vesicles/blisters/pustules/annular plaques
• lesions are generally located on lower limbs or dependent areas on the body

Systemic manifestations

• arthralgia
• fatigue
• fever
• anorexia

Question 9

Pemphigus vulgaris

Answer 9

Is an autoimmune reaction with IgG on cell surface antigens

Is life threating and needs to be treated

shows positive Nikolsky sign on lesions (lesions will brush off with pressure)

Question 10

Pemphigoid bullous

Answer 10

Autoimmune disorder caused by IgG deposit is on basement membrane autoantigens

Found usually in elderly and show numerous bullae/vesicles

Question 11

Sarcoidosis

Answer 11

Systemic granulomatous disease

Produces erythema nodosum as early skin finding
- becomes “apple jelly” papules on diascopy

Diagnosis requires = bilateral hilar lymphadenopathy on lungs

Question 12

Dermatomyositis

Answer 12

Idiopathic inflammatory myopathy that also targets the skin

Usually presents in childhood, if it is in adults need to rule out malignancy first

*shows heliotropic rash and gottron papules over the knuckles

Question 13

Scleroderma

Answer 13

Systemic sclerosis inflammatory reaction
- can be limited or diffuse (targets organs)

Always shows scleorising skin and Raynaud’s phenomenon (both types)

• also shows “rat-bitten” necrosis of fingertips
• skin is edematous without skin folds or wrinkles
• can also show diffuse telangiectesia if included in CREST syndrome

Females way more common (4:1)