Cutaneous Drug Eruptions Flashcards
Roughly what percentage of adverse drug reactions are cutaneous
30%
The skin is a common target for what type of drug reactions
Idiosyncratic drug reactions
Why are drug reactions under reported
Not all patients with a reaction will go to their doctor
What is a type 1 allergic reactions
Urticaria
What is a type 2 reactions
Pemphigus and pemphigoid
What is a type 3 reactions
Purura/ Rash that can’t be blanched
What is a type 4 reaction
T cell mediated. Erythema / rash
Immunologically -mediated reactions are dose dependent. True or False
False
Non-immunologically mediated reactions are dose dependent. True or false
True
Give some examples of non-immunologically mediated reactions
Eczema Drug-induced alopecia (chemotherapy) Phototoxicity Psoriasis Pigmentation Cheilitis Xerosis
A patient complains of burning/ tingling sensation when they are out in the sun. What is the diagnosis
Photosensitivity
How does a skin eruption usually resolve?
When the drug is withdrawn
Who is more at risk of developing a drug eruption? Males or females?
Females
What type of drugs are higher risks for drug eruptions
B lactam compounds, NSAIDS
High molecular weight/ hapten-forming drugs
What 3 things should be considered in a patient on multiple drugs?
A drug that is known to be most likely to cause an eruption
The time interval between exposure and development of skin reaction
History of previous exposure to the same drug
What is the most common type of drug eruption
Exanthematous
What type of reaction is an Exanthematous drug eruption
Type 4
Describe the usual appearance of an exanthematous drug eruption
Widespread symmetrically distributed rash
Pruritus and fever are also common
After how long does the reaction occur
4-21 days after first taking the drug
What are some indicators of a potentially severe reaction
Involvement of mucous membrane and face Facial oedema and erythema Widespread confluent erythema Blisters Shortness of breath Wheezing
Name some drugs which are associated with Exanthematous drug eruptions
Penicillins Sulphonamide antibiotics Erythromycin Streptomycin Allopurinol Anti-epileptics NSAIDs Phenytoin
Which immunoglobulin is usually associated with an Urticarial drug reaction
IgE (Type 1 )
Glucocorticoids can sometimes causes what type of drug eruption
Steroid acne
Pustular / Bullous drug eruption
What types of drugs can cause drug induced bullous pemphigoid
ACE inhibitors
Penicillin
Furosemide
Describe the apearance and locaation of fixed drug eruptions
Well demarcated round/ ovoid plaques.
Red, painful
Hands, genitalia, lips, oral mucosa (occcasionally)
What drugs are associated with fixed drug eruptions
Tetracycline, doxycycline
Paracetamol
NSAIDs
Carbamazepine
What type of light is usually a concern for phototoixc cutaneous drug reactions
UVA/ Visible
Name some drugs associated with phototoxicity
Antibiotics Thiazidde diruetics Chloropromazine NSAIDs Psoralens Amiodarone Immunosuppressants
What information about a drug reaction is required
The timing of symptoms to time of administration
When did the drug start/ stop
Photo of reaction
Why was the drug being taken
Drug history
Previous history of drug reactions/ allergy
What is the management for a patient with a drug reaction
Discontinue the drug is possible - use another one
Topical steroids may be useful
Antihistamines may be useful
Allergy bracelets
Report via the Yellow card scheme (medicines and healthcare products regulatory Agency)
