Hives Flashcards
What is the classic look of hives?
welts above the plane of the skin
movement and shape change
itchy
True or false: hives is only allergic based
false
hives is allergic and non-allergic based, anything is fair game
What are the allergic causes of hives?
foods
drugs
What are the non-allergic causes of hives?
URTIs (especially in kids)
pressure/vibration
cold temperature
nerves
What percentage of hives are caused by medications?
10%
What type of medication is the most common for causing hives?
antibiotics
What is dermatographism?
immunologic response to pressure applied to the skin
erythema and itch
begins within 5min of stimulation and persists for 15-30min
True or false: stress can cause hives
true
What is the clinical presentation of hives?
lesions last 1-24 hours up to several days
lesion location changes over time
very itchy
~20% of the population has had it
chronic form ~1%
usually benign
Why do we say that hives are USUALLY benign?
hives can be part of anaphylaxis or angioedema, thus they are no longer benign
What is the most common cause of hives in kids?
URTIs
When should we start to re-consider our hives diagnosis?
no itch
lesions have lasted longer than 24hrs in one spot
True or false: hives are worse during the day
false
worse at night due to lower cortisol levels
What percentage of penicillin skin reactions are allergic based?
1-3%
Will someone who had a previous reaction to penicillin have a worse reaction upon second exposure to the penicillin?
most people will not
Which treatment for hives is easier said than done?
avoiding the trigger(s)
What is the drug of choice for hives?
2nd gen antihistamines
-for itch!!
What is the dosing of 2nd gen antihistamines for hives?
regular dosing for a few days to weeks
What might an MD do if a 2nd gen antihistamine has not been helpful for hives after 2 weeks?
increasing the dose to 2-4 times a day
What are the adjunct therapies for hives?
1st gen antihistamines (maybe HS dose)
H2 blockers (not as valuable as H1 blockers)
leukotriene antagonists (not recommended)
oral steroid burst (severe cases)
What is chronic spontaneous urticaria?
recurrence of itchy wheals for at least 6 weeks
Are H1 antihistamines the perfect treatment for chronic spontaneous urticaria?
no, 10% of cases fail to control the disease
What should you never recommend for hives?
Benadryl cream
What is the verdict on using clobetasone or hydrocortisone for hives?
totally safe and makes sense but you are playing catch up because the hives move
