Emergency medicine Fellowship examination toolkit
16/01/2011
Amit Shetty
Bullous skin lesions
Causes / Appropriate TestsSolar/thermal injury / Diagnosis based on history and physical examination, with selected diagnostic imaging, endoscopy and pathology tests, as indicated.
Contactants, including
· Rhus tree
· Grevillea (Robyn Gordon type)
· Poison ivy
· Chemicals / Patch testing issometimes indicated. It should only be performed by a specialist practitioner, as reactions may be severe.
Bullous impetigo
Herpes simplex infection
Varicella zoster infection
Pemphigus / Pemphigus antibodies.
Pemphigoid / Pemphigoid antibodies.
Erythema multiforme
Porphyria, especially
· Porphyria cutanea tarda
· Porphyria variegata / Porphyrins - urine
Porphyrins, porphobilinogen - urine; porphyrins - faeces.
SLE
Epidermolysis bullosa / Molecular genetics, if available.
Dermatitis herpetiformis / Transglutaminase antibodies.
See alsoCoeliac disease.
Staphylococcal scalded skin syndrome
Toxic epidermal necrolysis
Graft versus host disease
Fixed drug reactions, especially
· Tetracycline
Vesicular skin lesions
Key Information / Appropriate TestsVesicle fluid for microscopy and bacterial culture, virus culture, detection, if infection is a suspected cause.
Scraping of vesicle base for virus culture, detection.
Biopsy may be indicated.
Viral infections
· Herpes simplex
· Varicella zoster
· Hand, foot and mouth disease / Clinical diagnosis, testing not required.
· Molluscum contagiosum
Bacterial infection
· Streptococcus pyogenes / Vesicles are usually a skin manifestation of severe underlying sepsis with septicaemia. Blood culture.
· Clostridium perfringens
Eczema
Trauma
· Burns
· Chemical damage
Adverse/fixed drug reactions
· Tetracycline
· Cotrimoxazole
· Topical applications
Dermatitis herpetiformis
Porphyria
Erythema multiforme
Causes/Associations / Appropriate TestsReview clinical findings; FBC; CRP.
Skin biopsy with IF if diagnosis uncertain.
Stevens-Johnson syndrome is a term used to describe a severe form of erythema multiforme with mucosal lesions and a poor prognosis.
Idiopathic
Drug reactions, especially;
· Sulphonamides
· Barbiturates
· Phenytoin
Infections, especially;
· Herpes simplex infection
· Mycoplasma infection
· Hepatitis B virus infection
· Leprosy
Connective tissue diseases
Neoplasia
Anaphylaxis
Causes / Appropriate TestsThe acute episode is an emergency, which must always be treated urgently.
Blood should be collected and stored for testing, including complement components C3 and C4; tryptase to confirm anaphylaxis, if indicated.
Subsequent investigation is required to establish cause: skin prick allergen testing with suspected allergens or allergen specific immunoglobulin E to detect specific IgE to relevant agents.
See also angioedema, urticaria
Drugs, especially
· Penicillins
· NSAID including aspirin
· General anaesthetic agents
Therapeutic/biological products, especially
· Blood transfusion, including / Immunoglobulin A to exclude selective IgA deficiency.
·
o Blood component therapy
· Allergen desensitisation
· Insect stings / SeeInsect sting sensitivity.
· Contrast agents / See anaphylactoid reaction
Food and other ingestants, especially
· Egg
· Milk
· Fish
· Peanuts
· Shellfish
· Other nuts
Contactants, especially
· Latex / SeeLatex allergy.
· Diethyl-meta-toluamide / Present in insect repellants.
· Bacitracin/neomycin
Exercise-induced
Idiopathic
Angioedema
Causes / Appropriate TestsMay be associated with Urticaria or Anaphylaxis.
Investigation should be appropriate to the clinical context: FBC, CRP, C3, C4.
Drugs, especially
· ACE inhibitors
· Penicillins
Foods and other ingestants, especially
· Preservatives
· Colouring agents
Insect stings / SeeInsect sting sensitivity.
Contactants
Allergens
Idiopathic
C1 inhibitor deficiency / C1 inhibitor immunological assay
Hereditary angioedema
Acquired
Cellulitis
Key Information / Appropriate TestsPus or aspirate from edge of lesion - wound swab microscopy and culture.
Blood culture if indicated.
Common pathogens
Streptococcus pyogenes / Anti-streptolysin O titre, anti-deoxyribonuclease B antibodies.
Staphylococcus aureus
Clostridium perfringens
Haemophilus influenzae / SeeHaemophilus influenzae infection.
Unusual pathogens
· Vibrio vulnificus / Predisposing disorders include cirrhosis, diabetes mellitus, haemochromatosis.
· Aeromonas hydrophila
Animal bites
· Pasteurella multocida
· Capnocytophaga canimorsus / See alsoWound infection.
Human bites
· Eikenella corrodens
Erythema nodosum
Causes/Associations / Appropriate TestsReview clinical findings.FBC, blood film. Skin biopsy (including subcutaneous fat) if diagnosis uncertain.
Idiopathic
Streptococcus pyogenes infection / Throat swab, wound swab – microscopy and culture (skin lesion); anti-deoxyribonuclease B antibodies, anti-streptolysin O titre.
Drug reactions, especially;
· Penicillins
· Sulphonamides
· Oral contraceptives
· Iodide
Sarcoidosis
Crohn's disease
Ulcerative colitis
Lymphoproliferative disorders
Tuberculosis
Leprosy
Purpura
Key Information / Appropriate TestsClinical assessment; FBC, blood film, platelet count.
Further investigation is unlikely to be productive unless there are clinical features suggestive of vasculitis or there is a personal or family history suggestive of a bleeding disorder.
The bleeding time and Hess test are neither sensitive nor specific and are not appropriate.
Thrombocytopenia
Vasculitis / Esp. Henoch-Schönleim purpura.
'Senile purpura' / Usually seen in older, fair skinned patients who have had prolonged solar exposure, with purpura typically on the forearms and dorsa of hands.
· Elderly patient
· Prolonged solar exposure
· Corticosteroid excess / SeeCushing's syndrome.
Scurvy
Porphyria cutanea tarda / Not a true form of purpura but may sometimes be confused with it. The lesions are typical blistering and heal with scarring.
Wound infection
Frequent Pathogens / Appropriate TestsMinor wound infections may just require local drainage (eg, removal of surgical suture) and do not require microbiological testing.
Wound swab or pus - microscopy and culture for moderate or severe infection, especially when there is spreading cellulitis or symptoms and signs of systemic infection.
Aspiration of pus is preferable to a swab of pus or wound.
If aspiration or swab of pus, or wound swab, is not possible, injection of 0.5-1.0 mL of saline followed by aspiration may provide a suitable specimen (eg, from areas of cellulitis).
Trauma, including surgery
· Staphylococcus aureus
· Streptococcus pyogenes
· Bacteroides fragilis
With soil, faecal contamination
· Clostridium perfringens
With water contamination
· Aeromonas hydrophila
· Vibrio spp
With fish-handling
· Erysipelothrix rhusiopathiae
With dog or cat bite
· Pasteurella multocida
· Capnocytophaga canimorsus (dogs)
With human bite
· Eikenella corrodens
Bruising
Causes / Appropriate TestsBruising is usually due to trauma and investigation should only be considered if the degree of bruising is disproportionate to the trauma.
Exclude use of aspirin, other NSAID: Where indicated, initial full blood count, PT/INR, APTT. If these are normal, and there is a low prior probability of underlying bleeding diathesis, no further investigation may be required.
Where von Willebrand disease is suspected, specific testing is required. In selected cases, other coagulation studies, with assays of specific coagulation factors and platelet function studies may be indicated.
See Bleeding Disorders.
Unrecognised trauma, especially
· Child abuse
Simple easy bruising / Easy bruising is common, particularly in females.
Skin 'fragility', due to / Clinical diagnosis.
· Elderly patients / Easy and extensive superficial bruising ('senile purpura') is common in the elderly and in those who have experienced prolonged, excessive solar exposure - investigation is inappropriate.
· Solar skin exposure
· Cushing's syndrome, including prolonged corticosteroid therapy
· Scurvy
A
Anaphylaxis 2
Angioedema 3
B
Bruising 6
Bullous skin lesions 1
C
Cellulitis 4
E
Erythema multiforme 2
Erythema nodosum 4
P
Purpura 5
V
Vesicular skin lesions 1
W
Wound infection 5