Dermatology

What three types of reactions are allergic? Which are non allergic?

Allergic- allergic contact dermatitis, photoallergic contact dermatitis, immunologic contact urticaria; Non allergic- irritation, photoirritation, nonimmunologic contact urticaria

In what section of the skin is a drug stored when it's absorbed in the skin?

stratum corneum

Describe the progression of acne vulgaris.

Androgens stimulate the sebaceous glands to produce sebum. This leads to follicular keratinization and obstruction. P. acnes, a normal skin flora resident, can then enter the comedone and multiply causing redness and inflammation leading to pustular and cystic acne.

True or False: Monotherapy for acne is preferred.

false; use of multiple drugs with various MOAs is preferred

If a person is prone to irritation, what formulation of clindamycin can you recommend?

water based gel and lotion

What is one complication associated with erythromycin use?

topical therapy can lead to antibiotic resistance, if resistance develops, d/c erythromycin and start systemic therapy

What antibiotic is effective in treatment of rosacea?

metronidazole

Metronidazole should not be used in what patients?

pregnant or nursing mothers and kids

What antibiotic is available in combo with sulfur to treat rosacea or acne vulgaris?

sodium sulfacetamide

What antibiotic causes serious adverse reactions from oral treatment?

dapsone

Which oral antibiotics are firstline? What others may be used?

Tetracyclines are first line however macrolides and trimethoprim/sulfamethoxazole can be used

What type of acne is sarecycline indicated for and who can use it? What is a potential benefit of this drug?

Indicated for once daily treatment of non nodular moderate to severe acne in patients 9 and up. This drug is a tetracycline derivative with a narrower spectrum of active which may result in lower rates of bacterial resistance

What is the MOA of benzoyl peroxide? How should you counsel a patient when taking benzoyl peroxide?

MOA: penetrate stratum corneum or follicular openings unchanged, then converts to benzoic acid and enacts antimicrobial activity. It is also comedolytic. Counsel: May cause peeling, application should be limited to a low concentration once daily for the first week then increase strength and frequency if tolerated

What is the MOA of retinoids? What are some adverse effects?

MOA: decrease size of sebum glands and production, anti inflammatory, comedolytic Adverse effects: Redness, dryness within 1st weeks resolved with continued use

Why should sunscreen be used when using retinoids?

retinoids can increase the tumorigenic potential of UV radiation

What are the uses for systemic retinoids?

approved for acne, psoriasis, cutaneous T cell lymphoma off-label: ichthyosis (excessive dry skin), rosacea, lupus

What patients are retinoids contraindicated in?

pregnant patients

Name some systemic retinoids and their indication.

Isotretinoin- recalcitrant nodular acne (monitor for depression; Acitretin- cutaneous manifestation of psoriasis; Bexarotene- cutaneous t cell lymphoma

Bexarotene is a contraindicated with _____.

DEET

What topical retinoid is photolabile and inactivated by benzoyl peroxide?

tretinoin

True or False: Adapalene is more stable than tretinoin.

true

What is the ideal treatment for comedonal noninflammatory acne?

topical retinoids (particularly adapalene) or benzoyl peroxide

What is the ideal treatment for severe papulopustular or moderate nodular acne?

isotretinoin monotherapy

What is the ideal treatment for mild-moderate papulopustular inflammatory acne?

adapalene/benzoyl peroxide or clindamycin/benzoyl peroxide

What is typically used as maintenance therapy?

topical retinoids

What retinoids are used to treat psoriasis?

acitretin and tazarotene

_____ must be strictly avoided when using acitretin.

alcohol

Which retinoid used for psoriasis is a prodrug?

tazarotene

How do vitamin D analogues benefit patients with psoriasis?

inhibit keratinocyte proliferation

What are some benefits and adverse effects of vitamin D?

Benefit: effectiveness doesn't decrease upon continuous use; Adverse effects: transient Ca level elevation, itching, dryness, burning, irritation, erythema

What keratolytic agents can be used for psoriasis? What type of psoriasis is it useful for?

salicylic acid and coal tar; especially good for scalp psoriasis

True or False: Adalimumab targets IL-23, a cytokine involved in the development of psoriatic lesions.

False; guselkumab blocks IL-23, adalimumab blocks TNF-alpha

What is the target for ustekinumab?

IL-22 and 23

Before biologic use, what screening needs to be done?

screen for clinically significant infection and hx of malignancy

What is the target, indication, and black box warning of brodalumab?

IL-17 receptor A antagonist; treats mod-severe plaque psoriasis in adults who are candidates for systemic and photo therapy who failed to respond or loss response to other systemic therapy; Black Box- suicide ideation and behavior

What drug classes can be used to treat excema?

topical corticosteroids, biologic, calcineurin inhibitors

What biologic is indicated for atopic dermatitis? What does it target?

dupixent, IL-4

What type of atopic dermatitis are calcineurin inhibitors indicated for and what are some side effects and black box warning?

mild-moderate; burning sensation to area of application; Black Box- skin cancer

List topical vehicles, starting with those most suitable for wet skin conditions and ending with those suitable for dry skin.

tinctures, wet dressings, lotions, gels, aerosols, powders, pastes, creams, foams, ointments