Skin Signs and Systemic Disease Flashcards
What is erythema Multiforme?
Hypersensitivity reaction most commonly triggered by Herpes simplex but also mycoplasma, cytomegalovirus, and drugs (penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs COCP and nevirapine).
How does erythema multiforme appear?
Appearance
Minor form – Erythematous well-defined round lesions appear on extensor surfaces of peripheries, palms and soles. Evolve at different stages into pathognomonic target lesions with minimal mucosal involvement.
Major form – associated systemic upset and severe mucosal involvement (note this is distinct from Stephen Johnsons syndrome)
How is erythema multiforme managed?
None required in most cases
Potent topical steroids or oral antihistamines may relieve any rash or pruritis
Treat the cause
What is erythema migrans and how is the condition managed?
Skin changes seen with Lyme’s disease. Best way to diagnose as serology is difficult. The majority will have a history of a tick bite. Lesion seen in 80% of cases and develops 7-10 days after the bite.
Management
Referral to specialist
Antibiotics – doxycycline, amoxicillin or cefuroxime
What is the apperance of erythema migrans?
Papule becomes a spreading red ring lasting week to months.
Bulls-eye rash
What is livedo reticularis?
Non-blanching vague pink mottled skin causes by capillary dilatation and stasis in venules most commonly seen on the leg. This is usually physiological if continuous but discontinuous is seen in connective tissue diseases, vasculitis, cholesterol embolic ad Hyperviscosity states.
What is dermatitis herpetiform?
This is an autoimmune blistering skin disorders associated with coeliac disease, caused by deposition of IgA in the dermis.
Diagnosis via skin biopsy and direct immunofluorescence showing deposition of IgA in agranular patter in the upper dermis.
How does dermatitis herpetiform present?
Itchy, vesicular lesions on the extensor surfaces such as elbows, knees, and buttocks.
Management
Gluten free diet
Dapsone
What are the features of pyoderma gangrenosum?
Features
Typically, on the lower limbs
Initially small red papule
Later deep, red, necrotic ulcers with a violaceous border
May be accompanied by systemic symptoms e.g. Fever, myalgia
What causes pyoderma gangrenosum?
Idiopathic in 50% Inflammatory bowel disease: ulcerative colitis, Crohn's Rheumatoid arthritis, SLE Myeloproliferative disorders Lymphoma, myeloid leukaemias Monoclonal gammopathy (IgA) Primary biliary cirrhosis
How is pyoderma gangrenosum managed?
The potential for rapid progression is high in most patients and most doctors advocate oral steroids as first-line treatment
Other immunosuppressive therapy, for example ciclosporin and infliximab, have a role in difficult cases
