Pharm: Papulosquamous Flashcards
What are NSAID pseudoallergic reactions based on?
COX-1 inhibiting properties of the NSAID
What are NSAID allergic reactions caused by?
IgE mediated
What is the triad of comorbidities that make up the asthma exacerbated respiratory diseases?
- asthma
- chronic rhinosinusitis w/nasal polyps
- chronic urticaria
Type 1 pseudoallergic NSAID reaction
- timeline
1 - 3 hours
Type 1 pseudoallergic NSAID reaction
- sx
Mostly Respiratory • Rhinorrhea • Nasal congestion • Periorbital edema and/or injection of the conjunctiva • Bronchospasm • Laryngospasm • +/- Hives and/or angioedema • severe: flushing, abd pain, diarrhea, hypotension
Type 2 pseudoallergic NSAID reaction
- timeline
30-90 min
Type 2 pseudoallergic NSAID reaction
- sx
mostly cutaneous
• Pts with chronic urticaria
• Develop exacerbation of their hives, sometimes with angioedema
• Occurs after taking COX-1 inhibitors (ASA and some NSAIDs)
Type 3 pseudoallergic NSAID reaction
- timeline
30 - 90 min
Type 3 pseudoallergic NSAID reaction
- sx
Mostly Cutaneous
• Pts without chronic urticaria
• Acute urticaria and or angioedema (facial areas, periorbital skin, lips, mouth)
• May have intermittent episodes of unexplained urticaria unrelated to NSAID ingestion
• Likely related to COX-1 mechanisms, can usually tolerate highly selective COX-2 inhibiting NSAIDs
Type 6 allergic NSAID reaction
- time frame
minutes to an hour
Type 6 allergic NSAID reaction
- sx
- Severe urticaria and/or angioedema
* Anaphylaxis
Description of a phototoxic skin reaction
- Nonallergic cutaneous reaction
- Results from direct tissue or cellular damage following UV irradiation of a phototoxic agent that was ingested or applied to the skin
- The “threshold concentration” of chemical/drug must have been met
- Severity is proportional to drug dose
- Looks like exaggerated sunburn, evolve within minutes to hours of sun exposure, restricted to sun exposed skin
What 4 drugs cause phototoxic skin reactions
- Tetracycline
- thiazide
- retinoid
- NSAIDs
How long does it take for a photoallergic reaction to occur?
24-48 hours after sun exposure
Description of a photoallergic reaction
- Delayed hypersensitivity reaction
- Same as allergic contact dermatitis to photoallergen
- Must have had previous exposure to the photoallergen
- Typically pruritic, eczematous eruptions on sun-exposed areas of skin
- More often to topical vs. systemic agents
What four agents cause photoallergic reactions?
- sunscreen with PABA
- topical NSAID
- sulfonamides
- thiazides
Treatment for phototoxic reaction to a drug
- DC offending agent ASAP
- Treat like a sunburn: cool compress, emollient, oral analgesics. Avoid topical anesthetics (possibility of contact allergy)
- Broad spectrum sunscreen with UVA protection
Treatment for photoallergic reaction to a drug
- DC offending agent ASAP
- Treat like contact allergy: topical corticosteroids to reduce pruritus and inflammatory response.
How to treat pruritus associated with pityriasis rosea?
- medium potent (4,5) corticosteroids
- topical antipruritic lotions containing pramoxine, methol, oral antihistamines
Pityriasis rosea
- treatment with local anesthetics
- Local anethetics block conduction along axonal membranes to relieve itching and pain
- Do not use on large surface areas over long period of time
- Do not use on <2 yo
- Pramoxine, lidocaine, benzocaine
Pityriasis rosea
- treatment with counterirritants
- Camphor and menthol
* antipruritic
What is first line treatment for localized cutaneous lichen planus
- body
- face/intertriginous skin
- Body: high potency or super high potency topical corticosteroids
- Face or intertriginous skin: medium to low potency topical steroid
What is first line treatment for generalized lichen planus
- Monotherapy with topical corticosteroids not practical
* Topicals used as adjunct to systemic or phototherapy
What is second line treatment for lichen planus
- Acitretin (Soriatane)
- oral retinoid
- second line d/t ADR, only use if can’t manage with corticosteroids or light therapy
- can induce remission or produce marked improvement
Acitretin (Soriatane) ADR
- Xerosis
- Alopecia
- Hypertriglyceridemia
- Increased liver enzymes
- Myalgias and arthralgias
- CNS: hyperesthesias and paresthesias
- Increased creatinine and phosphokinase
Acitretin (Soriatane) and pregnancy
CI for three years after discontinuing drug!
Role of emollients in psoriasis tx
- Valuable and inexpensive adjuncts to tx
- Keeps psoriatic skin soft and moist, minimizing sx of itching and tenderness
- Regular use: decreased itching, reduced scales, enhanced penetration of topical therapies
- Prevents irritation and potential for subsequent development of new lesions
What is considered the cornerstone tx for psoriasis?
topical steroids
What are vitamin D analogues often used in the tx of psoriasis?
- Calcipotriene
- Calcitriol
What role does tar plan in the tx of psoriasis
- Precise MoA unknown, has apparent antiproliferative effect
- Helpful as an adjunct to topical corticosteroids
Pt education for the use of tar to treat psoriasis
- Can stain hair, skin, clothing
- Use at night and wear inexpensive night clothes don’t mind ruining.
- Unpleasant odor
- Shampoo – ensure product reaches the scalp, leave in place 5-10 min before rinsing out
Topical retinoid used to treat psoriasis
Tazarotene (tazorac gel and cream)
What is the risk of tazarotene with pregnancy
- category X
- must use effective contraception
What is the limitation associated with tazarotene
limited to 20% BSA
What are the two calcineurin inhibitors?
- tacrolimus
- pimecrolimus
What is the role of the two calcineurin inhibitors in the tx of psoriasis?
- well suited for use on facial and intertriginous areas
- reduce the need for topical steroid
What is the basic MoA of salicylic acid?
keratolytic agent
Role of salicylic acid in tx of psoriasis
- Often combined with other topical therapies – corticosteroids and topical immunomodulators
- Avoid use with children and other salicylates
What is the role of anthralin in the treatment of psoriasis
- Effective in thick plaque psoriasis
- Less effective overall than topical vitamin D or potent corticosteroid therapy
Pt education for the use of anthralin in the tx of psoriasis
- Not suitable for face, flexures, or genitals
- Red-brown stain (temp on skin, permanent on clothes)
- Avoid application to surrounding unaffected skin (can use petrolatum or zinc oxide to surrounding skin to protect)
- Wash off affected area after desired contact period
How to dose anthralin
titrated in strength and contact time
Nonpharmacologic interventions for treatment of rosacea
- Avoidance of triggers of flushing
- Gentle skin care
- Sun-protection:
- Use of cosmetic products to mask redness: green tint with flesh colored on top
What are potential triggers for rosacea flushing
temp extremes sunlight spicy food alcohol exercise acute psych stressors medications menopausal hot flashes etc.
Skin care for rosacea
- four categories
- Emollients: frequent skin moisturizing. Repair and maintain cutaneous barrier function
- Non-soap detergents: beauty bars, mild cleansing bars, many liquid facial cleansers are better than traditional soaps
- Avoid skin irritating products: toners, astringent, chemical exfoliating agents (alpha hydroxyl acids), manual exfoliation, etc.
- Broad spectrum sunscreen: daily application of broad spectrum sunscreen min SPF 30
What is drug treatment for rosacea-associated facial erythema
brimondine (Mirvaso) gel
- Strongest evidence for efficacy for persistent facial erythema in rosacea
- Vasoconstrictor
What are serious ADR for brimondine (Mirvaso)
- Risk of vascular insufficiency and hypotension: avoid in pts with depression, cerebral or coronary insufficiency, Raynauds, orthostatic hypotension, thromboangiitis obliterans, scleroderma, Sjogren, severe CVD
- Caution also in pts using anti-hypertensives, cardiac glycosides, CNS depressants, MAOIs
3 topical treatments for papulopustular rosacea
- metronidazole
- azeleic acid
- ivermectin
What is first line oral drug for systemic tx of papulopustular rosacea
oral tetracycline
What is first line treatment for early phymatous rosacea
retinoids
define SPF
sun protection factor
What does broad spectrum mean related to sunscreen
Passed test procedures for measuring effectiveness against both UVA and UVB radiation
Recommendations for sunscreen:
- SPF for body
- SPF for lips
- Timeframe for application
- Timeframe for reapplication
- Body: SPF 15+ (Derm recommends SPF 30+)
- Lips: SPF 30+
- Apply 15-30 min before sun exposure – doesn’t work instantly
- Reapply: min every 2 hours, more often if sweating or swimming
Recommendations for using sunscreen in an infant
- Small amount of SPF 15+ can be applied to limited areas on <6 months old if no way to avoid sun
- Zinc oxide and titanium are good options bc don’t chemically bind to the skin, may be less irritating
