Drug Eruptions & Wart
Warts
What is it
Common benign epidermal lesions associated with HPV
How does it spread
Via human contact
Virus enters keratinocyte through breaks in skin
Immunocompromised patients are at greater risk
Presentation
Thickening of skin, Hyperkeratosis
Painless and usually no sequalae
Development
Eventually develop immunity to virus, and resolves spontaneously
Children 1-2 years, so don’t treat
Management
Aim to activate immune system to recognise & destroy wart
Most topical treatments >6 weeks
Treat factors that enhance spread e.g. cuts, abrasions, hand dermatitis
Warts exposed to moisture are more difficult to treat
Topical Wart Paints
Podophyllin resin
Alcoholic based with keratolytic agent
Anti-mitotic action, can use for genital warts
Physical Therapies
Cutterage (if scarring isn’t an issue)
Cryotherapy (wart necrosis/blistering, immune resp)
Tretinoin cream esp planar warts on face
Second Line
CO2 laser excision
Sensitization to allergen
Drug Eruptions
Basis
ADR often manifested on skin
More likely in polypharmacy, elderly, immuno-compromised
Any drugs is capable of producing a skin reaction
Early recognition & drug cessation
Watch out for cross reactivity within drug classes
And across classes e.g. penicillins and cephalosporin 3-6%
Common metabolites e.g. between anticonvulsants
If not severe, may rechallenge
Essential to document & inform patient
Diagnosis
Clinical features
Temporal relationship between drug use and rash development
Biopsy findings
David Thiu (B. Pharmacy)
Drug Eruption types
Urticaria
Presentation
Red patches & wheals
May be round, form rings, map-like pattern or giant patches
May occur with angio-oedema
Symptoms
Itching, swelling, redness with central clearing
Causes
Due to vasodilation & transudation of fluid from cutaneous blood vessels
Can be physical, due to cold, due to drugs/foods
Management
Avoid
Trigger factors
Vasodilators (alcohol, heat)
Substances that trigger histamine release
Sedating antihistamine E.g. promethazine, chlorpheniramine, cyproheptadine
Less sedating antihistamine E.g. cetirizine, loratadine
Consider using IM antihistamine
Other
Examthem
Photosensitivity
Erythema Multiforme
Steven’s Johnson
Toxic Epidermal Necrolysis
Oral prednisolone
S/C adrenaline
Either morbiliform OR Maculopapular
Presentation
Measle like, small red, macular
Flat and round lesions
Begin on trunk then spreads, Itchy
Causes:
Antibiotics (penicillin, co-trimoxazole, cephalosporin), carbamazepine
Treatment:
Withdrawal, emollients, topical CS
Causes:
NSAIDS, phenothiazines, tecracyclines,
sulfonamides, thiazides, ciprofloxacin, amiodarone
Treatment
Withdrawal, sunscreens, emollient +/- Topical CS
Presentation
Mild & self limiting
Urticucated papules +/- mucous membranes
Whitish border easily recognised
Ballae in severe form
Causes
Recurrent herpes simplex, mycoplasma infection
Presentation
More severe form, usually drug induced
Extensive involvement of mucuous membranes (oral, ocular, genital) with
generalized bullae (fluid filled blisters)
Causes
Allopurinol, CBZ, phenytoin, NSAIDs, sulfonamides, tetracyclines, gold
Treatment
Withdrawal, care of mucous membranes, Oral prednisolone until lesion clear
Presentation
Similar to burns, most serious/lifesthreatening
Low grade fever, malaise, sore throat
2-3 days later, widespread Erythema, large flaccid bullae
Loss of epidermis/mucosal surfaces, leaves denuded and painful dermis
Loss of fluid & electrolyte balance, thermal control
Causes
Allopurinol, CBZ, phenytoin, NSAIDs, sulfonamides
Ampicillin, Amoxycillin, lamotragine, nevirapine, barbiturates,
cephalosporins
ICU or burns unit, avoid renal failure & electrolyte imbalance, barrier nursing
to avoid sepsis
Oral prednisolone or cyclosporin
Treatment:
David Thiu (B. Pharmacy)