Emergency Dermatology Flashcards
What is the essential management of all dermatological emergencies?
- Full supportive care - ABC of resuscitation
- Withdrawal of precipitating agents
- Management of associated complications
- Specific treatment (highlighted below under each condition)
What are causes of Urticaria, Angioedema and 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 (in some cases of angioedema)
What causes Urticaria?
- Urticaria 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.
- Local mediator release from mast cells can be induced by immunological or non-immunological mechanisms.
What is the presentation of Urticaria and Angiodema?
- Urticaria is a swelling involving the superficial dermis, raising the epidermis. Causes itchy wheals
- Angioedema involves deeper swelling involving the dermis and subcutaneous tissues. Causes swelling of tongue and lips
How does anaphylaxis present?
Anaphylaxis (also known as anaphylactic shock):
- Bronchospasm
- Facial and laryngeal oedema
- Hypotension
- Can present initially with urticaria and angioedema
What is the management of Urticaria, Angioedema and Anaphylaxis?
- Urticaria: Antihistamines
- Severe acute urticaria and angioedema: Corticosteroids
- Anaphylaxis: Adrenaline, corticosteroids and antihistamines
What is the definition and causes of Erythema Nodosum?
Hypersensitivity response to a variety of stimuli. Causes are:
- Group A beta-haemolytic streptococcus
- Primary tuberculosis
- Pregnancy
- Malignancy
- Sarcoidosis
- Inflammatory bowel disease (IBD)
- Chlamydia
- Leprosy
What is the presentation of Erythema Nodosum?
- The shins are the most common site
- Discrete tender nodules which may become confluent
- 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
What is Erythema Multiforme?
- Erythema multiforme, often of unknown cause, is an acute self- limiting inflammatory condition with herpes simplex virus being the main precipitating factor. Other infections and drugs are also causes.
- Mucosal involvement is absent or limited to only one mucosal surface.
What is this?
Erythema Multiforme
What is this?
Stevens-Johnson syndrome
haracterised by
mucocutaneous necrosis with at least two mucosal sites involved. Skin involvement may be limited or extensive.
What is associated with Stevens-Johnson syndrome?
Drugs or combinations of infections or drugs are the main associations.
What is seen on histopathology for Stevens-Johnson syndrome?
- Epithelial necrosis with few inflammatory cells is seen on histopathology.
- The extensive necrosis distinguishes Stevens- Johnson syndrome from erythema multiforme.
- Stevens-Johnson syndrome may have features overlapping with toxic epidermal necrolysis including a prodromal illness.
What is Toxic Epidermal Necrosis?
- Toxic epidermal necrosis which is usually drug-induced, is an acute severe similar disease characterised by extensive skin and mucosal necrosis accompanied by systemic toxicity.
- On histopathology there is full thickness epidermal necrosis with subepidermal detachment.
What is the management of Toxic Epidermal Necrosis?
- Early recognition and call for help
- Full supportive care to maintain haemodynamic equilibrium
What are complications of Erythema multiforme, Stevens-Johnson syndrome and Toxic epidermal necrolysis?
- Mortality rates are 5-12% with SJS and >30% with TEN with death often due to:
- Sepsis
- Electrolyte imbalance
- Multi-system organ failure
What is Acute meningococcaemia?
- A serious communicable infection transmitted via respiratory secretions; bacteria get into the circulating blood
- Gram negative diplococcus - Neisseria meningitides
What is the presentation of Acute Meningococcaemia?
- Features of meningitis e.g. headache, fever, neck stiffness
- Septicaemia e.g. hypotension, fever, myalgia
- Non-blanching purpuric rash on the trunk and extremities, which may be preceded by a blanching maculopapular rash, and can rapidly progress to ecchymoses, haemorrhagic bullae and tissue necrosis
What is the management of Acute Meningococcaemia?
- Antibiotics (e.g. benzylpenicillin)
- Prophylactic antibiotics (e.g. rifampicin) for close contacts (ideally within 14 days of exposure)
What are complications of Acute meningococcaemia?
- Septicaemic shock
- Disseminated intravascular coagulation
- Multi-organ failure
- Death
What is Erythroderma?
Exfoliative dermatitis involving at least 90% of the skin surface
Prognosis is largely depends on the underlying cause and overall mortality rate ranges from 20 to 40%
What are causes of Erythroderma?
- Previous skin disease (e.g. eczema, psoriasis)
- Lymphoma,
- Drugs (e.g.sulphonamides, gold, sulphonylureas, penicillin, allopurinol, captopril)
- Idiopathic
What is the presentation of Erythroderma?
- Skin appears inflamed, oedematous and scaly
- Systemically unwell with lymphadenopathy and malaise
What is the management of Erythroderma?
