Chapter 6: Principles of Management

Most common skin disorders can be treated with a formulary of cost-effective, widely available topical and oral products. Topical medications are effective for most common skin disorders and they have fewer serious adverse side effects when compared with their oral counterparts. Oral medications may be needed if a skin disease is widespread or more severe.

There are several things to consider before prescribing a topical product such as the active ingredient, the vehicle, and the quantity to dispense.

The vehicle of a topical product may be as important as the active ingredient. Table 6-1 lists commonly used vehicles. "If it's dry, wet it and if it is wet, dry it" is still a good general guideline for treatment of common dermatoses. Most skin disorders, especially the chronic dermatoses (eg, psoriasis, chronic contact dermatitis), are "dry"; therefore, ointments are preferred as they are more moisturizing. Also, ointments do not contain preservatives that can cause stinging and burning. The main problem with ointments, is that they are greasy and can stain clothing and bedding. Creams are a good option for the "wet" dermatoses, such as acute contact dermatitis, and other blistering or exudative dermatoses. They are also a good option for adults who do not want to use an ointment. However, some cream preparations are slightly drying and preservatives and other ingredients in the vehicle may sting or burn.

The quantity of medication to be dispensed and the amount of medication that is needed per application are important considerations in prescription medications, especially topical steroids and calcineurin inhibitors.

There are a few general rules that can be used to estimate the quantity of topical medication a patient will need; however, the required amount may vary a great deal depending on the age of the patient, body size, type of vehicle, and how thickly the product is applied. In general:

• Approximately 30 g of cream will cover the entire adult body for 1 application.

• As an approximation, infants will need one fifth of the adult quantity, children two fifths of the adult quantity, and adolescents two thirds of the adult quantity.¹

It is also important to give instructions to patients on what quantity of medication they need to apply per application. The fingertip unit (FTU) is a commonly used measurement.² A FTU is the amount of medication dispensed (squeezed) from a tube with a 5 mm nozzle that covers the skin of the index finger from the tip to the distal crease (Figure 6-1). One FTU is equal to approximately 0.5 g. One FTU will cover an area of skin equivalent to the area covered by 2 hands. Another option for estimating larger quantities is the use of a standardized kitchen tablespoon. One tablespoon holds slightly less than 15 g of a cream or ointment which will cover approximately half of an adult body.

Topical medications are usually packaged in increments of 15 g, most commonly in tubes and bottle sizes of 15, 30, 45, and 60 g. Many generic topical steroid medications can be dispensed in jars of larger sizes, typically at a lower cost per gram.

The cost of medications is an increasingly important issue and may affect a patient's decisions about the purchase and use of a prescription medication. There are generic forms of most of the commonly used topical medications. A study published in 2012 reported that in the United States, the average generic dermatologic medication was $55.84 compared with $115.72 for brand name products resulting in a cost saving of almost 55%.³

There were concerns about the quality of topical generic medications several years ago, but recent studies on selected products have shown that they are equivalent in efficacy to brand name medications.³ There are, however, some products such as emollient steroid creams, augmented steroids, combination medications, and certain vehicle preparations that are available only as branded products.

Topical steroids are used for a wide range of inflammatory skin disorders such as dermatitis and papulosquamous skin disorders. They have anti-inflammatory, antiproliferative, and immunosuppressive effects on the skin. In the United States topical steroids are ranked from class 1 to 7 with superpotent steroids in class 1 and the least potent steroids in class 7.⁴ The steroids in any one class have equivalent potency, so a limited formulary of topical steroids is sufficient in most cases (Table 6-2).

There are many factors to consider when prescribing a topical steroid including the nature of the disease to be treated, the location of the rash, the amount of steroid needed, duration and frequency of treatment, and the age of the patient (Table 6-3).⁵

The risks of topical steroids are less severe than those associated with the use of oral corticosteroids; however, in certain situations the topical adverse effects can be cosmetically distressing to the patient and damaging to the skin (Table 6-4).⁶ Systemic adverse reactions, similar to those seen with systemic steroids, can occur with the use of more potent topical steroids, especially in children.

Most common inflammatory dermatoses can be managed without systemic steroids. However, there are a few indications for their short-term use, such as widespread severe allergic contact dermatitis (eg, dermatitis due to poison ivy) and in some cases of atopic dermatitis that are unresponsive to other therapies. Chapter 8 contains additional information about the use of systemic steroids in these conditions.

Topical calcineurin inhibitors (tacrolimus and pimecrolimus) are nonsteroidal, immunosuppressant medications that are Food and Drug Administration (FDA) approved for use as a second-line therapy for short-term use in moderate to severe atopic dermatitis. Stinging and burning are common side effects of these medications. Pimecrolimus (Elidel) cream 1% and tacrolimus (Protopic) 0.03% ointment are approved for patients 2 years and older and tacrolimus 0.1% ointment is approved for adults.

Several studies have been done on the off-label use of tacrolimus and pimecrolimus in cases in which the long-term use of topical steroids is contraindicated such as in dermatoses on the face (especially in the periorbital area) and other areas of thin skin. These studies have shown that calcineurin inhibitors are effective in seborrheic dermatitis, perioral dermatitis, intertriginous psoriasis, and vitiligo.⁷

Tacrolimus and pimecrolimus have black box warnings that state in part "Although a causal relationship has not been established, rare cases of malignancy (eg, skin and lymphoma) have been reported in patients treated with topical calcineurin inhibitors." Therefore continuous long-term use of topical calcineurin inhibitors in any age group should be avoided, and application limited to areas of involvement with atopic dermatitis. The association with increased malignancy has been a subject of controversy in the literature.⁸ There are ongoing 10-year observational registries of children ages 2 to 17 who have used a topical calcineurin inhibitor.

The barrier function of the skin is impaired in many of the common dermatoses, especially in atopic dermatitis. It is essential that the barrier function be restored and maintained with use of moisturizers.⁹ Moisturizers should be applied liberally at least twice a day including immediately after bathing. The use of a low detergent bar or liquid soap is also important in the maintenance of the barrier. Examples of moisturizers and cleansers that can be used in patients with dermatitis and other inflammatory skin disorders are listed in Table 8-2.

Creams or lotions with ceramides, lactic acid, or urea may be helpful in some conditions, such as dry skin or dermatitis. At lower concentrations, lactic acid and urea act as moisturizers (humectants) and at higher concentrations, they act as keratolytic agents, which are especially helpful in thick fissured skin. The following are examples of these products:

• Ceramides: CeraVe Moisturizing Lotion and Cream and Cetaphil Restoraderm lotion. Prescription-only creams include Atopiclair and Mimyx Cream.

• Lactic acid: AmLactin Moisturizing Lotion and Lac-Hydrin Lotion.

• Urea: Carmol 10 and 20 Cream or Lotion. Carmol 40 is prescription only.

Tub baths with emollients added to the water are an efficient method of moisturizing the entire skin's surface. Aveeno Soothing Bath Treatment (colloidal oatmeal powder) and RoBathol Bath Oil (cottonseed oil) are examples of such products. Bath products may make the tub slippery, so caution is needed when entering or exiting the bathtub.

Wet dressings are a safe, cost-effective treatment for dermatoses that are vesicular or have crusts or exudate such as acute contact dermatitis, atopic dermatitis, bullous diseases, and impetigo.¹⁰ Topical emollients or topical steroid creams can be applied before or after the wet dressings. Table 6-5 covers the materials and procedure for wet dressings.

Over-the-counter lotions containing calamine, camphor, menthol, or pramoxine are commonly used to reduce the symptoms of pruritus.¹¹ Some of the widely available products and their active ingredients are as follows:

• Aveeno Anti-Itch Lotion (calamine and pramoxine)

• Eucerin Calming Itch Relief Lotion (menthol)

• Prax Lotion (pramoxine)

• Sarna Original Anti-Itch Lotion (camphor and menthol)

• Sarna Sensitive Anti-Itch Lotion (pramoxine)

Oral antihistamines for urticaria are listed in Table 14-3. They are also commonly used for treatment of pruritus due to other etiologies. However, in conditions such as atopic dermatitis it may be the soporific effect of the sedating antihistamines that is responsible for their efficacy in the treatment of pruritus.¹¹

Superficial fungal infections such as tinea pedis, tinea cruris, and tinea corporis will usually respond to nonprescription topical antifungal agents, such as clotrimazole, miconazole, terbinafine, and tolnaftate. However, prescription medications may be needed in cases that do not respond to these products. Prescription and nonprescription topical antifungal agents are listed in Table 10-3.

Oral antifungal medications are needed for treatment of fungal infections in the scalp and nails and in some cases of fungal infections of the skin that do not respond to topical agents. These are listed in Tables 10-1 and 10-2 and in other sections of Chapter 10.

Oral and topical medications for herpes simplex and herpes zoster are covered in Tables 11-1 and 11-2.

Topical and oral medications for the treatment of acne and rosacea are covered in Chapter 15.

• Oral antibiotics for skin infections are covered in Chapter 12.

• Topical antibiotics are useful for treatment of localized areas of impetigo and superficial bacterial skin infection. Mupirocin ointment and cream 2% and retapamulin ointment 1% are examples of prescription topical antibiotics. Over-the-counter topical antibiotics can also be used but they have a higher rate of risk for allergic contact dermatitis. These include bacitracin, neomycin, and triple antibiotic (polymyxin, neomycin, and bacitracin) ointments.

Topical medications for the treatment of scabies and lice are covered in Tables 13-1 and 13-2.

Sunscreens are very important for the prevention of ultraviolet light (UVL)–related disorders such as skin cancer and photoaging (eg, wrinkles).¹² Several factors are important in the selection of a sunscreen including the sun protection factor (SPF) rating, the active ingredient, and the vehicle (Table 6-6). The SPF is a measurement of a sunscreen's ability to protect the skin against UVL in a laboratory setting. For example, if someone normally sunburns after 20 minutes of sunlight exposure, theoretically a SPF 15 sunscreen would protect him or her from burning for 15 × 20 minutes or 5 hours. However, there are several factors that in real life use of sunscreen reduce the level of protection. For maximum effectiveness sunscreens should be used as follows:

• Broad-spectrum sunscreens with SPF of 15 to 30 or higher should be used

• Applied 15 to 30 minutes before exposure

• Applied at the amount of 30 g (1 oz) per application if an entire adult body is to be covered

• Reapplied every 2 hours or after swimming or excessive sweating

• Kept at room temperature, not stored in car

FDA sunscreen regulations on labeling of sunscreens were changed in 2012. Some of these rules include criterion for the term "broad spectrum" and water-resistant claims will be specific (ie, sunscreen remains effective for 40 or 80 minutes after swimming). There will also be a limit on the SPF that can be claimed.

Clothing commonly worn in the summer such as cotton, rayon, and linen may not offer sufficient protection from UVL for some fair-skinned or photosensitive individuals.¹³ Polyester fabrics offer higher level of protection, but for prolonged sun exposure, sun protective clothing is a better option. The following are examples of companies that offer a wide range of sun protective clothing, swimwear, and hats for children and adults:

• Coolibar: www.coolibar.com

• Sun Precautions: www.sunprecautions.com

• Tilley Endurables: www.tilley.com

Some people are unwilling to limit UVL exposure because they want a tan. Sunless tanning products are an option for some of those individuals who want to have the appearance of a tan without exposure to the sunlight or tanning beds. These products usually contain dihydroxyacetone (DHA) that interacts with the amino acids in the stratum corneum to produce a temporary tanned appearance to the skin. DHA in a lower concentration in a daily moisturizer (eg, Jergens Natural Glow and Neutrogena Build-A-Tan) is associated with less streaking. Sunless tanning products are not sunscreens and do not protect against sunburns.

Additional information about sun protection can be found at the Web site of the Skin Cancer Foundation (www.skincancer.org) and the American Academy of Dermatology (www.AAD.org).

Compliance with the use of topical medications is low. Studies show that many patients do not actually purchase their prescriptions or use the medications less frequently or in smaller quantities than recommended.¹⁴ Compliance is particularly low in chronic conditions such as atopic dermatitis, psoriasis, and acne. Some of these compliance problems can be addressed by clinicians asking about patients' preferences for various treatment regimens, setting realistic treatment goals, the use of clear written instructions about the importance and proper use of the prescribed medications, the use of medication reminder cell phone applications, and a follow-up visit to assess the patient's response and compliance with the treatment plan.

Patients with chronic skin disorders (eg, psoriasis, atopic dermatitis, chronic pruritus) have higher rates of anxiety and depression than healthy control subjects.¹⁵ These negative emotional states can trigger or worsen skin disease, setting off a vicious cycle. Patients with skin disorders and psychiatric comorbidities are best managed by a team approach including clinicians in primary care, mental health, and dermatology. These patients are often treated with standard psychotropic medications commonly used for anxiety and depression.¹⁶ Nonpharmacologic management such as psychotherapy, hypnosis, biofeedback, support groups, meditation, and other stress reduction techniques are also beneficial.¹⁷

There are several free Web sites that have more detailed information about prescription and nonprescription products. The following is a list of selected sites:

• www.dailymed.com has the most recent FDA labels (package inserts) for many commonly used prescription medications. It is a free Web site of the US National Library of Medicine.

• www.nlm.nih.gov/medlineplus/druginformation has patient information for prescription products and herbs and supplements.

• www.drugstore.com lists the ingredients in many common topical nonprescription products.

• www.drugs.com contains information about generic availability of medications.