WK 12- Dermatological Emergencies Flashcards
(35 cards)
1
Q
What drugs most commonly cause cutaneous drug eruptions
A
- Antibiotics: penicillins, cephalosporins and sulphonamide → most common drug reaction seen
- Antiretro-virals
- Non-steroidal anti-inflammatory drugs
- Anti-epileptic drugs
- Allopurinol
2
Q
What is a exathematic drug reastion
A
- Most common skin reaction due to drugs
- a generalised erythematous maculopapular rash rashes are frequently itchy.
- The main differential diagnosis is a viral exanthemas→ comes on as a result of virus
- Usually resolves 1 to 2 weeks after cessation of the drug.
3
Q
What is a urticarial drug reaction
A
- Urticaria is the second most common type of acute drug reaction
- commonest as a result of antibiotics, particularly penicillins, angiotensin converting enzyme inhibitors, aspirin and NSAIDs
- usually presents within 24 to 36 hours of ingestion of a drug
- There are four types of urticarial drug reactions→ uncomplicated urticaria, angioedema, serum sickness, anaphylaxis
4
Q
What is uncomplicated urticaria
A
Presents with wheals→ raised, oedematous, erythematous round or polycyclic lesions which are “evanescent” (moving around constantly)
- Such rashes are often but not always very itchy because of histamine release
- Most drug induced reactions cease after 6 weeks of no drug
- When urticaria lasts for more than six weeks, it is arbitrarily defined as “chronic urticaria”
- type 1 hypersensitivity
5
Q
What is the ddx for uncomplicated urticaria
A
-Because urticaria is frequently targetoid it is often confused with erythema multiforme (one of the ddx), causing concern because of the serious implications of this condition→BUT EM DOES NOT MIGRATE
6
Q
What is angio-oedema
A
- Not as common→ due to dermal swelling
- Angio-oedema is a subset of urticaria involving deeper tissues which presents with swelling usually of the face, eyelids, hands and feet.
- It may be severe enough to close both eyes and make facial features unrecognisable
- It is usually migratory but may not do so
7
Q
What is serum sickness
A
- Not as common
- Serum sickness is a type of immunological reaction where a drug forms immune complexes.
- In this case a typical urticarial reaction is accompanied by fevers, angio-oedema, lymphadenopathy and arthralgias.
- Nephritis and endocarditis may occur and there is often an eosinophilia→ due to complexes depositing in kidneys
- Serum sickness is a Type III Hypersenstivity response
8
Q
What is anaphylaxis
A
- Anaphylaxis is a life-threatening emergency caused by massive release of histamine. It may:
- Be precipitated by any of the agents that are implicated in acute urticaria
- Occur within minutes of ingestion of a precipitant.
- The first sign is often dizziness and skin itching and burning. Patients often experience feelings of panic and anxiety. Vomiting and abdominal pain may occur due to GIT involvement.
- An urticarial rash associated with angio-oedema of the face, neck and airway is frequently present. Wheezing occurs from bronchospasm→ heard on auscultation
- Patients may progress rapidly to circulatory collapse leading to hypotension and shock.
- Laryngeal oedema and bronchospasm lead to respiratory arrest.
9
Q
What is the treatment of anaphylaxis
A
Adrenaline comes in 1:1000 ampoules containing 1mg of adrenaline in 1ml.
- Doses for IMI adrenalin 1:1000 are:
- Small patient: <50kg (very small woman, thin teenager, child >25kg) : 0.25ml
- Average patient: 50-100kg (most adults): 0.50ml
- Large patient (obese adult): 0.75ml
10
Q
What is the difference between a photoallergic and photoxic skin allergies
A
- both need to ingest a drug which you will become sensitised to, and when exposed to sunlight a toxic reaction will occur in the sun-exposed area→ photoallergic rash will not stay in the area of sun exposure whilst phototoxic
- rashes resemeble sunburn and may blister
- caused by doxycycline (acne and anti-malarial), furosemide
11
Q
What is a eczematous and lichenoid drug eruption
A
- Rashes which resemble chronic eczema or lichen planus may be but rarely are, caused by drugs
12
Q
What is a vasculitis drug reaction
A
- Drugs may cause purpuric drug reactions
- With the exception of aspirin, drugs uncommonly cause purpuric rashes and serious vasculitic eruptions due to drugs are rare.
13
Q
What is TEN
A
- Toxic epidermal necrolysis (TEN) is the most feared and serious cutaneous drug reaction and is one of the most serious and life threatening dermatological emergencies.
- TEN is a drug reaction that involves not only skin but can cause multi-organ failure. It is important to be aware of the most often implicated drugs which are
- can cause significant loss of epidermal barrier
14
Q
What is erythema multiforme
A
- Erythema multiforme is not usually life threatening although it can be very severe. It is not a systemic disease and affects only skin and mucous membranes.
- Is usually the result of infection with herpes simplex virus or mycoplasma pneumonia,
- It has a wide clinical spectrum ranging from a mild rash without mucosal involvement (EM minor) to a widespread blistering eruption associated with severe mucosal ulceration of mouth, eyes, vagina and urethra
- The classic lesion of EM is a “target lesion” which is typically a raised, round papule with a darker dusky or blistered centre, surrounded by a pale oedematous ring with a red edge.
- Lesions are relatively small, up to 3cm in diameter and occur in crops. The lesion is fixed and does not migrate→ distinguishes it from urticaria, with which it is commonly confused. Lesions last approximately 1-2 weeks before resolving.
15
Q
What is DRESS
A
The drug hypersensitivity syndrome knows as DRESS (drug rash with eosinophilia and systemic symptoms) is a very severe multisystem reaction
- Patients present 3-6 weeks after commencing the drug with fever, malaise, sore throat, facial oedema, a generalised erythematous rash which progresses to erythroderma.
- Systemically, lymphadenopathy, hypereosinophilia and other haematological abnormalities, hepatitis, nephritis, pneumonitis and myocarditis may occur→ very systemically unwell
- This condition may last many weeks and has a mortality of about 10%.
16
Q
What is erythroderma
A
Erythroderma is a term that is used to describe any skin disease that involves 90% or more of the body surface area. Such skin diseases are usually inflammatory, erythematous and scaly
There are five main causes of erythroderma:
1. Dermatitis
2. Psoriasis
3. Cutaneous lymphoma Drug reactions
4. Pityriasis rubra pilaris
-Systemic disturbance is usually present due to disruption of the skin barrier. As a result, hypothermia, fluid and protein loss, electrolyte disturbance and cardiac failure may occur. The patient is often shivery and unwell.
17
Q
What is vasculitis
A
Vasculitis is a skin reaction caused by inflammation of blood vessel walls. It has a characteristic histopathological appearance and is diagnosable on skin biopsy.
- The size of the vessels involved determines the clinical appearance of the rash.
- Superficial vessels tend to present with “palpable purpura”, ulceration and necrosis while deeper involvement may produce nodules and plaques
18
Q
What are the causes of vasculitis in adults
A
Approximately 50% of adult patients with cutaneous vasculitis have an idiopathic condition. Of those where the cause is known there are four main etiological groups in adults.
- Associated with viral or bacterial infection, particularly meningococcal disease but accompanying any form of sepsis.
- Associated with an underlying connective tissue disease particularly systemic lupus erythematosus and rheumatoid arthritis.
- Hypersensitivity reactions to drugs.
- In association with haematological dyscrasia or malignancy.
19
Q
What are the causes of vasculitis in children
A
- Infection associated, most often with streptococcal infection
- Henoch-Schonlein Purpura, a characteristic IgA mediated vasculitis.
- Acute haemorrhagic oedema, a benign probably viral reaction pattern.
- The most common infections to cause vasculitis are meningococcal disease and streptococcal infection. Hepatitis B and C and HIV disease may also be implicated. Patients with any form of septicaemia may develop a cutaneous vasculitis.
20
Q
What is small vessel vasculitis- what do they look like/where are they found
A
- aka “leucocytoclastic vasculitis”
- The clinical hallmark of small vessel vasculitis is “palpable purpura”, or purpuric lesions that are slightly raised and do not blanch.
- The lesions are most often found in “dependent areas” meaning areas where immune complexes are likely to settle due to gravity. For a mobile patient this means the lower legs, for a bed bound patient, the back, buttocks and legs.
21
Q
What is the difference between a photoallergic and photoxic skin allergies
A
- both need to ingest a drug which you will become sensitised to, and when exposed to sunlight a toxic reaction will occur in the sun-exposed area→ photoallergic rash will not stay in the area of sun exposure whilst phototoxic
- rashes resemeble sunburn and may blister
- caused by doxycycline (acne and anti-malarial), furosemide
22
Q
What is a eczematous and lichenoid drug eruption
A
- Rashes which resemble chronic eczema or lichen planus may be but rarely are, caused by drugs
23
Q
What is a vasculitis drug reaction
A
- Drugs may cause purpuric drug reactions
- With the exception of aspirin, drugs uncommonly cause purpuric rashes and serious vasculitic eruptions due to drugs are rare.
24
Q
What is TEN
A
- Toxic epidermal necrolysis (TEN) is the most feared and serious cutaneous drug reaction and is one of the most serious and life threatening dermatological emergencies.
- TEN is a drug reaction that involves not only skin but can cause multi-organ failure. It is important to be aware of the most often implicated drugs which are
- can cause significant loss of epidermal barrier
25
What is erythema multiforme
- Erythema multiforme is not usually life threatening although it can be very severe. It is not a systemic disease and affects only skin and mucous membranes.
- Is usually the result of infection with herpes simplex virus or mycoplasma pneumonia,
- It has a wide clinical spectrum ranging from a mild rash without mucosal involvement (EM minor) to a widespread blistering eruption associated with severe mucosal ulceration of mouth, eyes, vagina and urethra
- The classic lesion of EM is a "target lesion" which is typically a raised, round papule with a darker dusky or blistered centre, surrounded by a pale oedematous ring with a red edge.
- Lesions are relatively small, up to 3cm in diameter and occur in crops. The lesion is fixed and does not migrate→ distinguishes it from urticaria, with which it is commonly confused. Lesions last approximately 1-2 weeks before resolving.
26
What is DRESS
The drug hypersensitivity syndrome knows as DRESS (drug rash with eosinophilia and systemic symptoms) is a very severe multisystem reaction
- Patients present 3-6 weeks after commencing the drug with fever, malaise, sore throat, facial oedema, a generalised erythematous rash which progresses to erythroderma.
- Systemically, lymphadenopathy, hypereosinophilia and other haematological abnormalities, hepatitis, nephritis, pneumonitis and myocarditis may occur→ very systemically unwell
- This condition may last many weeks and has a mortality of about 10%.
27
What is erythroderma
Erythroderma is a term that is used to describe any skin disease that involves 90% or more of the body surface area. Such skin diseases are usually inflammatory, erythematous and scaly
There are five main causes of erythroderma:
1. Dermatitis
2. Psoriasis
3. Cutaneous lymphoma Drug reactions
4. Pityriasis rubra pilaris
-Systemic disturbance is usually present due to disruption of the skin barrier. As a result, hypothermia, fluid and protein loss, electrolyte disturbance and cardiac failure may occur. The patient is often shivery and unwell.
28
What is vasculitis
Vasculitis is a skin reaction caused by inflammation of blood vessel walls. It has a characteristic histopathological appearance and is diagnosable on skin biopsy.
- The size of the vessels involved determines the clinical appearance of the rash.
- Superficial vessels tend to present with "palpable purpura", ulceration and necrosis while deeper involvement may produce nodules and plaques
29
What are the causes of vasculitis in adults
Approximately 50% of adult patients with cutaneous vasculitis have an idiopathic condition. Of those where the cause is known there are four main etiological groups in adults.
1. Associated with viral or bacterial infection, particularly meningococcal disease but accompanying any form of sepsis.
2. Associated with an underlying connective tissue disease particularly systemic lupus erythematosus and rheumatoid arthritis.
3. Hypersensitivity reactions to drugs.
4. In association with haematological dyscrasia or malignancy.
30
What are the causes of vasculitis in children
1. Infection associated, most often with streptococcal infection
2. Henoch-Schonlein Purpura, a characteristic IgA mediated vasculitis.
3. Acute haemorrhagic oedema, a benign probably viral reaction pattern.
- The most common infections to cause vasculitis are meningococcal disease and streptococcal infection. Hepatitis B and C and HIV disease may also be implicated. Patients with any form of septicaemia may develop a cutaneous vasculitis.
31
What causes small vessel vasculitis
- damage to vessel walls by polymorphonuclear cells
- Many cases of small vessel vasculitis are idiopathic→ appears to be a reaction pattern to various exogenous agents: viral, bacterial and drug. It is often confined to skin although arthritis and arthralgias are common. In some cases there is renal involvement. It is often not a severe disease.
32
What is systemic/large vessel vasculitis
- Systemic vasculitis by definition do not just involve the skin → vasculitis rash may be the first sign.
- Involvement of other organ systems, notably kidneys, lung and liver, occurs and may result in life-threatening consequences. Larger and small vessels are involved.
33
What are the two most common types of systemic vessel vasculitis
Polyarteritis Nodosa and Wegener's granulomatosis.
| -Polyarteritis Nodosa (PAN) presents with nodules, livedo reticularis and ulcers.
34
-what tests would confirm the diagnosis of a uticarial rash caused by penicillin
No test present- process of slowly eliminating drugs to find the cause
35
what would the tx be for a drug induced rash
withdrawal the drug and see the response, can give anti-histamine if severely itchy-> but these only work for urticarial rashes
-could give corticosteroids for exanthomatic rashes
