Dermatologic Therapies

Basic Dermatology Curriculum

Last updated June 8, 2011 1

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Module Instructions

The following module contains a number of blue, underlined terms which are hyperlinked to the dermatology glossary, an illustrated guide to clinical dermatology and dermatopathology.

We encourage the learner to read all the hyperlinked information.

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Goals and Objectives

The purpose of this module is to help medical students gain familiarity with common dermatologic treatments.

By completing this module, the learner will be able to:• Estimate the amount of topical medication needed for therapy

based on frequency of application and body surface area involved

• Choose appropriate strengths of topical steroids based on age, body location and severity of dermatitis

• List side effects of prolonged use of topical steroids• Discuss the basic principles of medications used to treat acne• Discuss the basic principles of topical antifungals, oral

antihistamines and topical psoriasis medications

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Principles of Dermatologic Therapy

The efficacy of any topical medication is related to: • The active ingredient (inherent strength)• Anatomic location • The vehicle (the mode in which it is

transported)• The concentration of the medication

Solutions

Sprays

Gels

FoamsCreams

Oils

Ointments

Vehicles

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Vehicles

Ointments (e.g. Vaseline): lubricating, occlusive; greasy• USE for smooth, non-hairy skin; dry, thick, or hyperkeratotic lesions• AVOID on hairy and intertriginous (when skin is in contact with skin,

e.g. armpits, groin, pannus) areas

Creams (vanish when rubbed in): less greasy, drying effects; not occlusive, can sting, more likely to cause irritation (preservatives/fragrances)• USE for acute exudative inflammation, intertriginous areas

Lotion (pourable liquid): less greasy, less occlusive; may contain alcohol (drying effect on oozing lesion); penetrate easily, little residue• USE for hairy areas

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Vehicles (cont.)

Oils: less stinging than lotions or solutions• USE for the scalp, especially for people with coarse or very curly

hair

Gel (jelly-like): may contain alcohol, greaseless, least occlusive; dry quickly• USE for acne, exudative inflammation (e.g. acute

contact dermatitis); on scalp/hairy areas without matting

Foams (cosmetically elegant): spread readily, easier to apply; more expensive• USE for hairy areas; inflammation

• Sprays: Aerosols (rarely used), pump sprays 7

Medication Costs

Topical medications can be very expensive They are not all covered by insurance Over the counter (OTC) treatments are

generally cheaper than prescriptions Generics are less expensive than brand name

prescriptions It is helpful to know the costs of the medications

you prescribe and be able to tell the patient in advance what they should expect to pay

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What goes into a topical prescription?

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

• Generic name

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

• Generic name• Vehicle

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

• Generic name• Vehicle• Concentration

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

• Generic name• Vehicle• Concentration• Sig (directions)

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected

area (face) BID PRN for scaling #15 Grams RF3

• Generic name• Vehicle• Concentration• Sig• Amount

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Topical prescriptions

What goes into a prescription?• Desonide cream 0.05% apply to affected area

(face) BID PRN for scaling #15 Grams RF3

• Generic name

• Vehicle

• Concentration

• Sig

• Amount

• Refills16

Now Let’s Review Some Common Types of Medications

Used by Dermatologists

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Topical Corticosteroids

Topical steroids produce an anti-inflammatory response in the skin

They are effective for conditions that are characterized by hyperproliferation, inflammation, and immunologic involvement

They can also provide symptomatic relief for burning and pruritic lesions

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Topical Corticosteroids

Corticosteroids are organized into classes based on their strength (potency)• Therefore, steroids within any class are

equivalent in strength Strength is inherent to the molecule, not the

concentration Know one steroid from each class that would be

available to the majority of your patients (the generic in that class)

Topical Steroid Strength

Potency Class Example Agent

Super high I Clobetasol propionate 0.05%

High II Fluocinonide 0.05%

Medium III – V Triamcinolone acetonide ointment 0.1%Triamcinolone acetonide cream 0.1%Triamcinolone acetonide lotion 0.1%

Low VI – VIIFluocinolone acetonide 0.01%Desonide 0.05%Hydrocortisone 1%

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Topical Steroid Strength

Remember to look at the class not the percentage• Note that clobetasol 0.05%

is stronger than hydrocortisone 1%.

When several are listed, they are listed in order of strength• Note that triamcinolone

ointment is stronger than triamcinolone cream or lotion because of the nature of the vehicle

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Potency Class Example Agent

Super high I Clobetasol 0.05%

High II Fluocinonide 0.05%

Medium III – V Triamcinolone ointment 0.1%Triamcinolone cream 0.1%Triamcinolone lotion 0.1%

Low VI – VII

Fluocinolone 0.01%Desonide 0.05%Hydrocortisone 1%

Corticosteroid Selection

Super high potency (Class I) are used for severe dermatoses over nonfacial and nonintertriginous areas

• Scalp, palms, soles, and thick plaques on extensor surfaces

Medium to high potency steroids (Classes II-V) are appropriate for mild to moderate nonfacial and nonintertriginous areas

• Okay to use on flexural surfaces for limited periods Low potency steroids (Classes VI, VII) can be used for

large areas and on thinner skin• Face, eyelid, genital and intertriginous areas

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Local Side Effects of Topical Steroids

Local side effects of topical steroids include:• Skin atrophy • Telangiectasias• Striae

The higher the potency the more likely side effects are to occur.

To reduce risk, the least potent steroid should be used for the shortest time, while still maintaining effectiveness

• Acne• Steroid Rosacea• Hypopigmentation

Local Corticosteroid Skin Side Effects

Skin Atrophy Striae

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Local Corticosteroid Skin Side Effects

Hypopigmentation

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Systemic Side Effects of Topical Steroids

Systemic side effects are rare due to low absorption They can include:

• Glaucoma (when steroid applied to the eyelid)• Hypothalamic pituitary axis suppression• Cushing’s syndrome• Hypertension• Hyperglycemia

The higher the potency the more likely side effects are to occur

To reduce risk, the least potent steroid should be used for the shortest time, while still maintaining effectiveness

Duration of Treatment

Duration of treatment is limited by side effects In general:

• Super high potency: treat for <3 weeks• High and Medium potency: <6-8 weeks• Low potency: side effects are rare. Treat facial, intertriginous,

and genital dermatoses for 1-2 week intervals to avoid skin atrophy, telangiectasia, and steroid-induced acne

Stop treatment when skin condition resolves• To avoid rebound/flares: taper with gradual reduction of both

potency and dosing frequency every 2 weeks If the patient does not respond to treatment within these

guidelines, consider referral to a dermatologist27

Prescribing topical steroids

The following slides will review how to estimate the amount of medication to

prescribe according to the affected body surface area (BSA)

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Estimating BSA:Palm of Hand

1 Palm = 1% BSAUse the size of the patient’s palm, not your own

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Estimating topicals: Fingertip unit

Quantity of topical medication (dispensed from a 5mm nozzle) placed on pad of the index finger from distal tip to DIP joint

Fingertip unit (FTU) = 500 mg = treats 2% BSA

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2 palms 2 times a day = 30 grams / mo

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1 Palm = 1% BSA

FTU = 0.5 G

Covers 2 % BSA

Covers 2 palms

2 palms = 2% BSA

2 palms 2 times per day

= 1 gram per day

SO…GIVE 30 GRAMS FOR EVERY 2 PALMS OF AREA TO COVER (FOR 1 MONTH Rx)

1 Palm = 1% BSA

Practice Question 1

Take a look at the following photograph and decide how much BSA is affected. Then try to answer the question on the following slide.

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Practice Question

Which of the following prescriptions would you recommend for BID dosing for 1 month duration? Use 2% BSA.

a. Fluocinonide 0.05% ointment, apply to affected area (knees) BID, # 30 grams

b. Fluocinonide 0.05% ointment, apply to affected area (knees) BID, # 90 grams

c. Hydrocortisone 1% ointment, apply to affected area (knees) BID, # 30 grams

d. Hydrocortisone 1% ointment, apply to affected area (knees) BID, # 90 grams 33

Practice Question

Which of the following prescriptions would you recommend for BID dosing for 1 month duration? Use 2% BSA.

a. Fluocinonide 0.05% ointment, apply to affected area (knees) BID, # 30 grams (2 palms = 2% BSA = 30 grams for 1 mo BID)

b. Fluocinonide 0.05% ointment, apply to affected area (knees) BID, # 90 grams (for a 3 month supply)

c. Hydrocortisone 1% ointment, apply to affected area (knees) BID, # 30 grams (need a higher potency steroid for plaque psoriasis on the knees)

d. Hydrocortisone 1% ointment, apply to affected area (knees) BID, # 90 grams

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Estimating amounts

It takes ~30 grams to cover an average adult body (for one application)

Here is a rough estimation of amounts to prescribe for BID use for a month:• Face

• 30-45 grams

• Extensor surfaces of both arms• 120-150 grams

• Widespread on trunk, legs, arms:• 1-2 pounds (454 grams = 1 lb.)

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Estimating amounts: re-assess of follow-up

The best way to assure you are giving the right amount is to re-assess on follow-up• If your patient was given a 60-gram tube,

confirm they are using it according to instructions, and ask how long that tube lasts

• If a 60-gram tube only lasts them 2 weeks, they need 2 of them to last a month

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Estimating BSA: Rule of Nines

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The “rule of nines” is a good, quick way of estimating the affected BSA

Often used when assessing burns

The body is divided into areas of 9%

Less accurate in children Source: McPhee SJ, Papadakis MA: Current Medical Diagnosis and Treatment 2010, 49th Edition: http://www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc.

Pediatric Dosing

Children require adjusted dosage

Use a pediatric version of the rule of nines or the patient’s palm to estimate BSA

Remember that children, especially infants have a high body surface area to volume ratio, which puts them at risk for systemic absorption of topically applied medications

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Pediatric Dosing (cont.)

Low potency topical corticosteroids are safe when used for short intervals• Can cause side effects when used for extended durations

High potency steroids must be used with caution and vigilant clinical monitoring for side effects in children

Potent steroids should be avoided in high risk areas such as the face, folds, or occluded areas such as under the diaper

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Let’s move on to some more types of medications used by dermatologists

Medications commonly used to treat

Acne vulgaris

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Benzoyl peroxide

Benzoyl peroxide is a topical medication with both antibacterial and comedolytic (breaks up comedones) properties

Available as a prescription and over-the-counter, as well as in combinations with topical antibiotics

Patients should be warned of common adverse effects:

• Bleaching of hair, colored fabric, or carpet• May irritate skin; discontinue if severe

Available as a cream, lotion, gel, or wash41

Topical Antibiotics

Used to reduce the number of P. acnes and reduce inflammation in inflammatory acne

Do not use as monotherapy (often used with benzoyl peroxide to prevent the development of antibiotic resistance in the treatment of mild-to-moderate acne and rosacea)

• Erythromycin 2% (solution, gel)

• Clindamycin 1% (lotion, solution, gel, foam)

Metronidazole 0.75%, 1% (cream, gel) is used in the treatment of rosacea 42

Topical Retinoids (tretinoin, all trans retinoic acid)

Topical retinoids are vitamin A derivatives Used for acne vulgaris; photodamaged skin; fine

wrinkles, hyperpigmentation Patients should be warned of common adverse

effects:• Dryness, pruritus, erythema, scaling• Photosensitivity

Available as a cream or gel Do not apply at the same time as benzoyl peroxide

because benzoyl peroxide oxidizes tretinoin43

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Topical Acne Treatment: Side Effects

Topical acne treatments are often irritating and can cause dry skin • When using retinoids or benzoyl peroxide, consider

beginning on alternate days. Use a moisturizer to reduce their irritancy.

Topical agents take 2-3 months to see effect Patients will often stop their topical treatment too early

from “red, flakey” skin without improvement in their acne

Patient education is a crucial component to acne treatment

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Oral Antibiotics

Tetracycline, doxycycline, minocycline Use for moderate to severe inflammatory acne Often combined with benzoyl peroxide to prevent

antibiotic resistance If the patient has not responded after 3 months of

therapy with an oral antibiotic, consider: • Increasing the dose,• Changing the treatment, or • Referring to a dermatologist

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Oral Treatment: Side Effects

Tetracyclines (tetracycline, doxycycline, minocycline):• Are contraindicated in pregnancy and children age

<8 years• May cause GI upset (epigastric burning, nausea,

vomiting and diarrhea can occur)• Can cause photosensitivity (patients may burn

easier, which can be easily managed with better sun protection). Recommend sun block with UVA coverage for all acne patients on tetracyclines

Oral Tetracyclines: Patient Counseling

Major side effects:• Tetracycline: GI upset, photosensitivity• Doxycycline: GI upset, photosensitivity• Minocycline: GI upset, vertigo, hyperpigmentation

Patients need clear instructions• If taking for acne, it is okay to take them with food and

dairy products for tolerability of GI side effects• Take with full glass of water; avoids esophageal erosions• Tetracyclines do NOT interfere with birth control pills• It takes 2-3 months to see improvement

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Oral Isotretinoin

Oral isotretinoin, a retinoic acid derivative, is indicated in severe, nodulocystic acne failing other therapies

Should be prescribed by physicians with experience using this medication

Typically given in a single 5-6 month course Isotretinoin is teratogenic and therefore absolutely

contraindicated in pregnancy• Female patients must be enrolled in a FDA-mandated

prescribing program in order to use this medication

• Two forms of contraception must be used during isotretinoin therapy and for one month after treatment has ended

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Isotretinoin Side Effects

Common side effects of isotretinoin include: • Xerosis (dry skin)• Cheilitis (chapped lips)• Elevated liver enzymes• Hypertriglyceridemia

Individuals with severe acne may suffer mood changes and depression and should be monitored

Severe headache can be a manifestation of the uncommon side effect pseudotumor cerebri

Topical Antifungals

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Topical Antifungals

There are several classes of topical antifungal medications

Some classes are fungistatic (stop fungi from growing), others are fungicidal (they kill the fungi)

Not all conditions are treatable with topical antifungals (specifically, hair infections and nail infections do not respond to topical treatment and require systemic treatment)

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Topical Antifungals

The following are some examples of topical antifungals:• Imidazoles (fungistatic): Ketoconazole (Rx & OTC),

Econazole, Oxiconazole, Sulconazole, Clotrimazole (Rx & OTC), Miconazole (OTC)– Useful to treat candida and dermatophytes

• Allylamines and benzylamines (fungicidal): Naftifine, Terbinafine (OTC), Butenafine– Better for dermatophytes, but not candida

• Polyenes (fungistatic in low concentrations): Nystatin– Better for candida, but not dermatophytes

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Advantages of Topical Antifungals

Topical antifungals are preferred for most superficial fungal infections of limited extent.

Advantages include:• Relatively low cost• Acceptable efficacy • Ease of use• Low potential for side effects, complications,

or drug interactions

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Oral Antihistamines

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Antihistamines

Antihistamines are the most widely used agents for pruritus and chronic urticaria

1st Generation H1 antagonists are sedating• Anticholinergic side effects (e.g. memory impairment,

confusion, dry mouth, blurred vision) are dose-limiting• Use as a sleep aid at night for patients with pruritus• Use with caution in elderly due to increased fall risk, CNS

and anticholinergic effects

2nd Generation H1 antagonists are minimally sedating and require less frequent dosing than 1st generation H1

antihistamines55

Antihistamines

The following are examples of H1 antihistamines:

• 1st Generation• Diphenhydramine (OTC)

• Hydroxyzine (Rx, generic)

• Chlorpheniramine (OTC)

For most pruritic dermatoses that are not urticaria, 1st generation H1 antihistamines primarily work through their sedative effect rather than their anti-histaminic properties

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• 2nd Generation• Cetirizine (OTC)

• Loratadine (OTC)

• Fexofenadine (OTC)

Medications used in Psoriasis

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Skin Kinetics

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Some dermatoses are associated with a higher rate of epidermal turnover

• For example, the epidermis of psoriasis replicates too quickly

Topical therapies that inhibit keratinocyte proliferation are used in the treatment of psoriasis

They include:• Vitamin D analogs • Coal tar • Tazarotene

Psoriasis Treatment:Topical Vitamin D Analogs

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Calcipotriene (calcipotriol)• Inhibits keratinocyte proliferation

• Most common side effect is skin irritation

Calcitriol• Inhibits keratinocyte proliferation

• Stimulates keratinocyte differentiation

• Inhibits T-cell proliferation

• On more sensitive areas, less skin irritation than calcipotriol

Psoriasis Treatment

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Tar 2-5%• Antiproliferative effect• Disadvantages: stain clothing/hair/skin; messy; increases

photosensitivity• Can be combined with salicylic acid to penetrate thick

plaques

Tazarotene 0.05% and 0.1% • Topical retinoid used for acne, rosacea, psoriasis• Disadvantages: skin irritation; teratogenic; increases

photosensitivity• Can be combined with a Class II corticosteroid to reduce

irritation

Take Home Points

The efficacy of any topical medication is related to the strength, location, vehicle, and concentration

Topical medications can be very expensive When writing a prescription for a topical medication, include:

generic name, vehicle, concentration, directions, amount, # of refills

Corticosteroids are organized into classes based on their strength (potency)

Skin atrophy, acne, striae, and telangiectasias are potential local side effects of corticosteroid use

It takes ~30 grams to cover an average adult body (for one application)

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Take Home Points

Use benzoyl peroxide with topical antibiotics to prevent the development of antibiotic resistance in acne treatment

Lack of adherence is the most common cause of treatment failure in acne patients; patient education is crucial

Topical antifungals are preferred for most superficial fungal infections of limited extent

Antihistamines are the most widely used agents for pruritus and chronic urticaria

2nd Generation H1 antihistamines are less sedating that 1st generation H1 antihistamines

Many of the topical medications used in psoriasis inhibit keratinocyte proliferation

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Acknowledgements

This module was developed by the American Academy of Dermatology Medical Student Core Curriculum Workgroup from 2008-2012.

Primary authors: Alina Markova, Sarah D. Cipriano, MD, MPH; Timothy G. Berger, MD, FAAD; Patrick McCleskey, MD, FAAD.

Peer reviewers: Peter A. Lio, MD, FAAD; Ron Birnbaum, MD.

Revisions: Sarah D. Cipriano, MD, MPH. Last revised June, 2011.

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References

Berger T, Hong J, Saeed S, Colaco S, Tsang M, Kasper R. The Web-Based Illustrated Clinical Dermatology Glossary. MedEdPORTAL; 2007. Available from: www.mededportal.org/publication/462.

Drake LA, Dinehart SM, Farmer ER, et al. Guidelines of care for the use of topical glucocorticosteroids. American Academy of Dermatology. J Am Acad Dermatol 1996; 35:615.

Ference J, Last A. Choosing Topical Corticosteroids. Am Fam Physician 2009;79 (2):135-140.

Goldstein B, Goldstein A. General principles of dermatologic therapy and topical corticosteroid use. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA, 2011.

Hettiaratchy S, Papini R. ABC of burns. Initial management of a major burn: II – assessment and resuscitation. BMJ. 2004;329:101-103. 64

References

High Whitney A, Fitzpatrick James E, "Chapter 219. Topical Antifungal Agents" (Chapter). Wolff K, Goldsmith LA, Katz SI, Gilchrest B, Paller AS, Leffell DJ: Fitzpatrick's Dermatology in General Medicine, 7e: http://www.accessmedicine.com/content.aspx?aID=2969866.

Limb Susan L, Wood Robert A, "Chapter 230. Antihistamines" (Chapter). Wolff K, Goldsmith LA, Katz SI, Gilchrest B, Paller AS, Leffell DJ: Fitzpatrick's Dermatology in General Medicine, 7e: http://www.accessmedicine.com/content.aspx?aID=3003116.

Nelson A, Miller A, Fleischer A, Balkrishnan R, Feldman S. How much of a topical agent should be prescribed for children of different sizes? J Derm Treat 2006; 17:224-228.

Weller R, Hunter J, Dahl M. Clinical Dermatology. 2008; 55. Wolff K, Johnson R. Fitzpatrick’s Atlas of & Synopsis of Clinical

Dermatology. 2009; Sixth Ed. 65