Dermatology Flashcards
Describe how a patient with urticaria would present.
Itchy wheals
Describe the causes of urticaria.
- Idiopathic
- Food (e.g. nuts, sesame seeds, shellfish, dairy
products)
- Drugs (e.g. penicillin, contrast media, non-steroidal anti- inflammatory drugs (NSAIDs), morphine, angiotensin-converting enzyme inhibitors (ACE-i))
- Insect bites
- Contact (e.g. latex)
- Viral or
parasitic infections - Autoimmune
- Hereditary
Describe how you would manage a patient with urticaria.
- Antihistamines
- Corticosteroids is severe
Describe the potential complications of urticaria.
Normally uncomplicated
Describe the pathophysiology behind urticaria.
It is due to a local increase in permeability of capillaries and small venules.
A large number of inflammatory mediators (including prostaglandins, leukotrienes, and chemotactic factors) play a role but histamine derived from skin mast cells appears to be the major mediator.
Describe how a patient with angioedema would present.
Swelling of tongue and lips
Describe the causes of angioedema.
- Idiopathic
- Food (e.g. nuts, sesame seeds, shellfish, dairy
products)
- Drugs (e.g. penicillin, contrast media, non-steroidal anti- inflammatory drugs (NSAIDs), morphine, angiotensin-converting enzyme inhibitors (ACE-i))
- Insect bites
- Contact (e.g. latex)
- Viral or
parasitic infections - Autoimmune
- Hereditary
Describe how you would manage a patient with angioedema.
Corticosteroids
Describe the pathophysiology behind angioedema.
Deeper swelling involving the dermis and subcutaneous tissues
Describe the potential complications of angioedema.
- Asphyxia (unconsciousness)
- Cardiac arrest
- Death
Describe how a patient with anaphylaxis would present.
- Bronchospasm
- Facial and laryngeal oedema
- Hypotension
(NOTE: can present initially
with urticaria and angioedema)
Describe the causes of anaphylaxis.
- Idiopathic
- Food (e.g. nuts, sesame seeds, shellfish, dairy
products)
- Drugs (e.g. penicillin, contrast media, non-steroidal anti- inflammatory drugs (NSAIDs), morphine, angiotensin-converting enzyme inhibitors (ACE-i))
- Insect bites
- Contact (e.g. latex)
- Viral or
parasitic infections - Autoimmune
- Hereditary
Describe how you would manage a patient with anaphylaxis.
- Adrenaline
- Corticosteroids
- Antihistamine
Describe the potential complications of anaphylaxis.
- Asphyxia (unconsciousness)
- Cardiac arrest
- Death
Describe how a patient with erythema nodosum would present.
- Discrete tender nodules which may become confluent
- The shins are the most common site
Describe the causes of erythema nodosum.
- Group A beta-haemolytic streptococcus
- Primary tuberculosis
- Pregnancy
- Malignancy
- Sarcoidosis
- Inflammatory bowel disease (IBD)
- Chlamydia
- Leprosy
Describe how you would manage a patient with erythema nodosum.
- Reassurance and patient education
- Lesions continue to appear for 1-2 weeks and leave bruise-like discolouration as they resolve
- Lesions do not ulcerate and resolve without atrophy or scarring
Describe the pathophysiology behind erythema nodosum.
A hypersensitivity response to a variety of stimuli
Describe how a patient with erythema multiforme would present.
Mucosal involvement is absent or limited to only one mucosal surface
Describe the pathophysiology behind erythema multiforme.
Acute self- limiting inflammatory condition with herpes simplex virus being the main precipitating factor
Describe the causes of erythema multiforme.
- Often unknown
- Herpes simplex virus
- Drugs
Describe how you would manage a patient with erythema multiforme.
- Early recognition and call for help
Describe how a patient with Stevens-Johnson syndrome would present.
Mucocutaneous necrosis with at least two mucosal sites involved.
Skin involvement may be limited or extensive.
What can be seen on the histopathology of a patient with Stevens-Johnson syndrome?
Epithelial necrosis with few inflammatory cells