Thursday, December 23, 2010

Dermatology

DERMATOLOGY


Dermatology: Introduction


Dermatologic diseases will be discussed according to the types of lesions they cause. Therefore, in order to make a diagnosis, it is best to (1) identify the type of individual lesion the patient exhibits; (2) choose the morphologic category the lesions seem to fit (Table 6–1); and then (3) identify the specific features of the history, physical examination, and laboratory tests that will establish the diagnosis

Table 6–1. Morphologic categorization of skin lesions and diseases.
Pigmented Freckle, lentigo, seborrheic keratosis, nevus, blue nevus, halo nevus, atypical nevus, melanoma
Scaly Psoriasis, dermatitis (atopic, stasis, seborrheic, chronic allergic contact or irritant contact), xerosis (dry skin), lichen simplex chronicus, tinea, tinea versicolor, secondary syphilis, pityriasis rosea, discoid lupus erythematosus, exfoliative dermatitis, actinic keratoses, Bowen's disease, Paget's disease, intertrigo
Vesicular Herpes simplex, varicella, herpes zoster, dyshidrosis (vesicular dermatitis of palms and soles), vesicular tinea, dermatophytid, dermatitis herpetiformis, miliaria, scabies, photosensitivity
Weepy or encrusted Impetigo, acute contact allergic dermatitis, any vesicular dermatitis
Pustular Acne vulgaris, acne rosacea, folliculitis, candidiasis, miliaria, any vesicular dermatitis
Figurate ("shaped") erythema Urticaria, erythema multiforme, erythema migrans, cellulitis, erysipelas, erysipeloid, arthropod bites
Bullous Impetigo, blistering dactylitis, pemphigus, pemphigoid, porphyria cutanea tarda, drug eruptions, erythema multiforme, toxic epidermal necrolysis
Papular Hyperkeratotic: warts, corns, seborrheic keratoses
Purple-violet: lichen planus, drug eruptions, Kaposi's sarcoma
Flesh-colored, umbilicated: molluscum contagiosum
Pearly: basal cell carcinoma, intradermal nevi
Small, red, inflammatory: acne, miliaria, candidiasis, scabies, folliculitis
Pruritus1
 
Xerosis, scabies, pediculosis, bites, systemic causes, anogenital pruritus
Nodular, cystic Erythema nodosum, furuncle, cystic acne, follicular (epidermal) inclusion cyst
Photodermatitis (photodistributed rashes) Drug, polymorphic light eruption, lupus erythematosus
Morbilliform Drug, viral infection, secondary syphilis
Erosive Any vesicular dermatitis, impetigo, aphthae, lichen planus, erythema multiforme
Ulcerated Decubiti, herpes simplex, skin cancers, parasitic infections, syphilis (chancre), chancroid, vasculitis, stasis, arterial disease

1Not a morphologic class but included because it is one of the most common dermatologic presentations.

Principles of Dermatologic Therapy
Frequently Used Treatment Measures
Bathing
Soap should be used only in the axillae and groin and on the feet by persons with dry or inflamed skin. Soaking in water for 10–15 minutes before applying topical corticosteroids enhances their efficacy.
Topical Therapy
In general, topical agents used by prescription are supplied in only one strength. Exceptions include hydrocortisone (1% and 2.5%) and triamcinolone acetonide cream and ointment (0.025% and 0.1%) or solution (0.1%). There is little evidence that one concentration is different from another. Nondermatologists should become familiar with a few agents and use them properly rather than try to master the universe of topical agents.
Corticosteroids
Representative topical corticosteroid creams, lotions, ointments, gels, and sprays are presented in Table 6–2. Topical corticosteroids are divided into classes based on potency. There is little (except price) to recommend one agent over another within the same class. For a given agent, an ointment is more potent than a cream. The potency of a topical corticosteroid may be dramatically increased by applying an occlusive dressing over the corticosteroid. At least 4 hours of occlusion is required to enhance penetration. Such dressings may include gloves, plastic wrap, or plastic occlusive suits for patients with generalized erythroderma or atopy. Caution should be used in applying topical corticosteroids to areas of thin skin (face, scrotum, vulva, skin folds). Topical corticosteroid use on the eyelids may result in glaucoma or cataracts. One may estimate the amount of topical corticosteroid needed by using the "rule of nines" (as in burn evaluation; see Figure 37–2). In general, it takes an average of 20–30 g to cover the body surface of an adult once. Systemic absorption does occur, but adrenal suppression, diabetes, hypertension, osteoporosis, and other complications of systemic corticosteroids are very rare with topical corticosteroid therapy (see photograph); (see photograph).
Table 6–2. Useful topical dermatologic therapeutic agents.
Agent Formulations, Strengths, and Prices1
 
Apply Potency Class Common Indications Comments
Corticosteroids 
Hydrocortisone acetate Cream 1%: $3.60/30 g bid Low Seborrheic dermatitis Not the same as hydrocortisone butyrate or valerate!
Ointment 1%: $3.72/30 g Pruritus ani
Lotion 1%: $20.20/120 mL Intertrigo Not for poison oak!
        OTC lotion (Aquinil HC)
        OTC solution (Scalpicin, T Scalp)
Cream 2.5%: $8.95/30 g bid Low As for 1% hydrocortisone Perhaps better for pruritus ani
      Not clearly better than 1%
        More expensiveNot OTC
Alclometasone dipropionate (Aclovate) Cream 0.05%: $25.98/15 g bid Low As for hydrocortisone More efficacious than hydrocortisone
Ointment 0.05%: $54.19/45 g
Perhaps causes less atrophy
Desonide Cream 0.05%: $15.47/15 g bid Low As for hydrocortisone More efficacious than hydrocortisone
Ointment 0.05%: $39.88/60 g For lesions on face or body folds resistant to hydrocortisone
Can cause rosacea or atrophy
Lotion 0.05%: $33.39/60 mL Not fluorinated
Prednicarbate (Dermatop) Emollient cream 0.1%: $24.00/15 g bid Medium As for triamcinolone
May cause less atrophy
No generic formulations
Preservative-free
Ointment 0.1%: $22.86/15 g
Triamcinolone acetonide Cream 0.1%: $3.60/15 g bid Medium Eczema on extensor areas Caution in body folds, face
Ointment 0.1%: $3.60/15 g Economical in 0.5-lb and 1-lb sizes for treatment of large body surfaces
Lotion 0.1%: $42.44/60 mL Used for psoriasis with tar
Seborrheic dermatitis and psoriasis on scalp Economical as solution for scalp
Cream 0.025%: $3.00/15 g bid Medium As for 0.1% strength Possibly less efficacy and few advantages over 0.1% formulation
Ointment 0.025%: $5.25/80 g
Fluocinolone acetonide Cream 0.025%: $3.05/15 g bid Medium As for triamcinolone  
Ointment 0.025%: $4.20/15 g
Solution 0.01%: $11.00/60 mL bid Medium As for triamcinolone solution  
Mometasone furoate (Elocon) Cream 0.1%: $26.90/15 g qd Medium As for triamcinolone
Often used inappropriately on the face or in children
Not fluorinated
Ointment 0.1%: $23.90/15 g
Lotion 0.1%: $55.44/60 mL
Diflorasone diacetate Cream 0.05%: $36.78/15 g bid High Nummular dermatitis  
Ointment 0.05%: $51.86/30 g Allergic contact dermatitis
        Lichen simplex chronicus  
Amcinonide (Cyclocort) Cream 0.1%: $18.42/15 g bid High As for betamethasone  
Ointment 0.1%: $27.46/30 g
Fluocinonide (Lidex) Cream 0.05%: $10.61/15 g bid High As for betamethasone Economical generics
Gel 0.05%: $21.01/15 g Gel useful for poison oak Lidex cream can cause stinging on eczema
Ointment 0.05%: $21.25/15 g
  Lidex emollient cream preferred
Solution 0.05%: $27.27/60 mL  
Betamethasone dipropionate (Diprolene) Cream 0.05%: $7.80/15 g bid Ultra-high For lesions resistant to high-potency corticosteroids Economical generics available
Ointment 0.05%: $9.40/15 g
Lotion 0.05%: $30.49/60 mL
    Lichen planus  
    Insect bites  
Clobetasol propionate (Temovate) Cream 0.05%: $24.71/15 g bid Ultra-high As for betamethasone dipropionate
Somewhat more potent than diflorasone
Limited to 2 continuous weeks of use
Limited to 50 g or less per week
Cream may cause stinging; use "emollient cream" formulation
Generic available
Ointment 0.05%: $24.71/15 g
Lotion 0.05%: $53.10/50 mL
 
Halobetasol propionate (Ultravate) Cream 0.05%: $31.49/15 g bid Ultra-high As for clobetasol
Same restrictions as clobetasol
Cream does not cause stinging
Compatible with calcipotriene (Dovonex)
Ointment 0.05%: $31.49/15 g
Flurandrenolide (Cordran) Tape: $60.11/80" x 3" roll q12h Ultra-high Lichen simplex chronicus Protects the skin and prevents scratching
Lotion 0.05%: $90.00/60 mL
Nonsteroidal anti-inflammatory agents 
Tacrolimus2 (Protopic)
 
Ointment 0.1%: $80.72/30 g bid N/A Atopic dermatitis
Steroid substitute not causing atrophy or striae
Burns in 40% of patients with eczema
Ointment 0.03%: $75.53/30 g
Pimecrolimus2 (Elidel)
 
Cream 1%: $74.08/30 g bid N/A Atopic dermatitis Steroid substitute not causing atrophy or striae
Antibiotics (for acne) 
Clindamycin phosphate Solution 1%: $12.09/30 mL bid N/A Mild papular acne Lotion is less drying for patients with sensitive skin
Gel 1%: $38.13/30 mL
Lotion 1%: $53.06/60 mL
Pledget 1%: $46.40/60
Erythromycin Solution 2%: $6.90/60 mL bid N/A As for clindamycin Many different manufacturers Economical
Gel 2%: $24.73/30 g
Pledget 2%: $26.76/60
Erythromycin/Benzoyl peroxide (Benzamycin) Gel: $68.60/23.3 g bid N/A As for clindamycinCan help treat comedonal acne
No generics
More expensive
More effective than other topical antibiotic
Main jar requires refrigeration
Gel: $128.00/46.6 g
Clindamycin/Benzoyl peroxide (BenzaClin) Gel: $78.80/25 g bid   As for benzamycin
No generic
More effective than either agent alone
Gel: $143.53/50 g
Antibiotics (for impetigo)
Mupirocin (Bactroban) Ointment 2%: $44.65/22 g tid N/A Impetigo, folliculitis
Because of cost, use limited to tiny areas of impetigo
Used in the nose twice daily for 5 days to reduce staphylococcal carriage
Cream 2%: $41.35/15 g
Antifungals
Clotrimazole Cream 1%: $4.25/15 g OTC bid N/A Dermatophyte and Candida infections 
Available OTC
Inexpensive generic cream available
Solution 1%: $7.40/10 mL
Miconazole Cream 2%: $3.20/30 g OTC bid N/A As for clotrimazole As for clotrimazole
Other imidazoles
Econazole (Spectazole) Cream 1%: $16.28/15 g qd N/A As for clotrimazole
No generic
Somewhat more effective than clotrimazole and miconazole
Ketoconazole Cream 2%: $16.46/15 g qd N/A As for clotrimazole
No generic
Somewhat more effective than clotrimazole and miconazole
Oxiconazole (Oxistat) Cream 1%: $31.61/15 g bid N/A    
Lotion 1%: $56.23/30 mL
Sulconazole (Exelderm) Cream 1%: $13.07/15 g bid N/A As for clotrimazole
No generic
Somewhat more effective than clotrimazole and miconazole
Solution 1%: $28.13/30 mL
Other antifungals
Butenafine (Mentax) Cream 1%: $41.88/15 g qd N/A Dermatophytes
Fast response; high cure rate; expensive
Available OTC
Ciclopirox (Loprox) (Penlac) Cream 0.77%: $80.23/30 g bid N/A As for clotrimazole
No generic
Somewhat more effective than clotrimazole and miconazole
Lotion 0.77%: $162.77/60 mL
Solution 8%: $166.80/6.6 mL
Naftifine (Naftin) Cream 1%: $52.07/30 g qd N/A Dermatophytes
No generic
Somewhat more effective than clotrimazole and miconazole
Gel 1%: $91.68/60 mL
Terbinafine (Lamisil) Cream 1%: $8.15/12 g OTC qd N/A Dermatophytes
Fast clinical response
OTC
Antipruritics
Camphor/ menthol Compounded lotion (0.5% of each) bid–tid N/A Mild eczema, xerosis, mild contact dermatitis  
Pramoxine hydrochloride (Prax) Lotion 1%: $14.78/120 mL OTC qid N/A Dry skin, varicella, mild eczema, pruritus ani OTC formulations (Prax, Aveeno Anti-Itch Cream or Lotion; Itch-X Gel) By prescription mixed with 1% or 2% hydrocortisone
Doxepin (Zonalon) Cream 5%: $74.52/30 g qid N/A Topical antipruritic, best used in combination with appropriate topical corticosteroid to enhance efficacy Can cause sedation
Emollients
Aveeno Cream, lotion, others qd–tid N/A Xerosis, eczema Choice is most often based on personal preference by patient
Aqua glycolic Cream, lotion, shampoo, others qd–tid N/A Xerosis, ichthyosis, keratosis pilaris Mild facial wrinkles Mild acne or seborrheic dermatitis
Contains 8% glycolic acid
Available from other makers, eg, Alpha Hydrox, or generic 8% glycolic acid lotion
May cause stinging on eczematous skin
Aquaphor Ointment: $7.50/50 g qd–tid N/A Xerosis, eczema For protection of area in pruritus ani Not as greasy as petrolatum
Carmol Lotion 10%: $10.20/180 mL bid N/A Xerosis
Contains urea as humectant
Nongreasy hydrating agent (10%); debrides keratin (20%)
Cream 20%: $10.14/90 g
Complex 15 Lotion: $6.48/240 mL qd–tid N/A XerosisLotion or cream recommended for split or dry nails Active ingredient is a phospholipid
Cream: $4.82/75 g
DML Cream, lotion, facial moisturizer: $5.32/240 mL qd–tid N/A As for Complex 15 Face cream has sunscreen
Eucerin Cream: $5.10/120 g qd–tid N/A Xerosis, eczema
Many formulations made
Eucerin Plus contains alphahydroxy acid and may cause stinging on eczematous skin
Facial moisturizer has SPF 25 sunscreen
Lotion: $5.10/240 mL
Lac-Hydrin-Five Lotion: $10.12/240 mL OTC bid N/A Xerosis, ichthyosis, keratosis pilaris Rx product is 12%
Lubriderm Lotion: $5.03/300 mL qd–tid N/A Xerosis, eczema Unscented usually preferred
Neutrogena Cream, lotion, facial moisturizer: $7.39/240 mL qd–tid N/A Xerosis, eczema Face cream has titanium-based sunscreen
SBR Lipocream Cream: $8.23/30 g qd-tid N/A Xerosis, eczema Less greasy but effective moisturizer
Ceratopic Cream Cream: $39.50/4 oz bid N/A Xerosis, eczema Contains ceramide; anti- inflammatory and non-greasy moisturizer
U-Lactin Lotion: $7.13/240 mL qd N/A Hyperkeratotic heels Moisturizes and removes keratin

1Average wholesale price (AWP, for AB-rated generic when available) for quantity listed. AWP may not accurately represent the actual pharmacy cost because wide contractual variations exist among institutions. Source: Red Book Update, Vol. 26, No. 3, March 2007.
2Topical tacrolimus and pimecrolimus should only be used when other topical treatments are ineffective. Treatment should be limited to an area and duration to be as brief as possible. Treatment with these agents should be avoided in persons with known immunosuppression, HIV infection, bone marrow and organ transplantation, lymphoma, at high risk for lymphoma, and those with a prior history of lymphoma.
OTC, over-the-counter; N/A, not applicable.



Striae distensae. (Reproduced, with permission, from Bondi EE, Jegasothy BV, Lazarus GS [editors]: Dermatology: Diagnosis & Treatment. Orginally published by Appleton & Lange. Copyright © 1991 by The McGraw-Hill Companies, Inc.)


Skin atrophy on finger pad. (Courtesy of S Goldstein.) and Access Medicine.

Emollients for dry skin ("moisturizers")


Dry skin is not related to water intake but to abnormal function of the epidermis. Many types of emollients are available. Petrolatum, mineral oil, Aquaphor, and Eucerin cream are the heaviest and best. Emollients are most effective when applied to wet skin. They should be applied with the "grain" of the hairs rather than by rubbing up and down to avoid folliculitis. If the skin is too greasy after application, pat dry with a damp towel.

In some cases, lotions may be useful and are not as greasy as creams and ointments. The scaly appearance of dry skin may be improved by lactic acid or glycolic acid-containing products provided no inflammation (erythema or pruritus) is present. Moisturizers that mimic the skin's normal lipids and thus feel less greasy than ointments include SBR Lipocream and Ceratopic cream.
Drying agents for weepy dermatoses
If the skin is weepy from infection or inflammation, drying agents may be beneficial. The best drying agent is water, applied as repeated compresses for 15–30 minutes, alone or with aluminum salts (Burow's solution, Domeboro tablets) or colloidal oatmeal (Aveeno).

Topical antipruritics

Lotions that contain 0.5% each of camphor and menthol (Sarna) or pramoxine hydrochloride, 1%, are effective antipruritic agents (with or without 0.5% menthol, eg, Prax, PrameGel, Aveeno Anti-Itch lotion). Hydrocortisone, 1% or 2.5%, may be incorporated for its anti-inflammatory effect (Pramosone cream, lotion, or ointment). Doxepin cream 5% may reduce pruritus but may cause drowsiness. Pramoxine and doxepin are most effective when applied with topical corticosteroids. Monoamine oxidase inhibitors should be discontinued at least 2 weeks before treatment with doxepin.

Systemic antipruritic drugs

Antihistamines

H1-blockers are the agents of choice for pruritus when due to histamine, such as in urticaria. Otherwise, they appear to relieve pruritus only by their sedating effects. Except in the case of urticaria, nonsedating antihistamines are of little or no value in inflammatory skin diseases such as atopic dermatitis and are rarely indicated.
Hydroxyzine 25–50 mg nightly is typically used for its sedative effect in pruritic diseases. Sedation can limit daytime use. The least sedating antihistamines are loratadine and famotidine. Cetirizine causes drowsiness in about 15% of patients. Some antidepressants, such as doxepin, mirtazapine, and paroxetine can be effective antipruritics.

Sunscreens

Protection from ultraviolet light should begin at birth and will reduce the incidence of actinic keratoses and some nonmelanoma skin cancers when initiated at any age. The best protection is shade, but protective clothing, avoidance of direct sun exposure during the peak hours of the day, and daily use of chemical sunscreens are important.
Fair-complexioned persons should use a sunscreen with an SPF (sun protective factor) of at least 15 and preferably 30–40 every day. Sunscreens with high SPF values (> 30) afford some protection against UVA as well as UVB light exposure and may be helpful in managing photosensitivity disorders. Physical blockers (titanium dioxide and zinc oxide) are available in vanishing formulations. Aggressive sunscreen use should be accompanied by vitamin D supplementation in persons at risk for osteopenia (eg, organ transplant recipients).

American Academy of Family Physicians. Information from your family doctor. Saving your skin from sun damage. Am Fam Physician. 2006 Sep 1;74(5):815–6.


Complications of Topical Dermatologic Therapy

Complications of topical therapy can be largely avoided. They fall into several categories:

Allergy

Of the topical antibiotics, neomycin and bacitracin have the greatest potential for sensitization. Diphenhydramine, benzocaine, vitamin E, aromatic essential oils, and bee pollen are potential sensitizers in topical medications. Preservatives and even the topical corticosteroids themselves can cause allergic contact dermatitis.

Irritation

Preparations of tretinoin, benzoyl peroxide, and other acne medications should be applied sparingly to the skin. Sunscreens may cause irritation or an acne-like eruption.

Overuse

Topical corticosteroids may induce acne-like lesions on the face (steroid rosacea) and atrophic striae in body folds.


Melanocytic Nevi (Normal Moles)

In general, a benign mole is a small (< 6 mm), well-circumscribed lesion with a well-defined border and a single shade of pigment from beige or pink to dark brown (see photograph). The physical examination must take precedence over the history, though a reliable history that a lesion has been present without change for decades is obviously a comfort.



Normal mole (nevus).


Moles have a normal natural history. In the patient's first decade of life, moles often appear as flat, small, brown lesions. They are called junctional nevi because the nevus cells are at the junction of the epidermis and dermis. Over the next 2 decades, these moles grow in size and often become raised, reflecting the appearance of a dermal component, giving rise to compound nevi. Moles may darken and grow during pregnancy. As white patients enter their seventh and eighth decades, most moles have lost their junctional component and dark pigmentation and undergo fibrosis or other degenerative changes. Still, at every stage of life, normal moles should be well-demarcated, symmetric, and uniform in contour and color.
Abbasi NR et al. Early diagnosis of cutaneous melanoma: Revisiting the ABCD criteria. JAMA. 2004 Dec 8;292(22):2771–6.

Atypical Nevi
The term "atypical nevus" or "atypical mole" has supplanted "dysplastic nevus." The diagnosis of atypical moles is made clinically and not histologically, and moles should be removed only if they are suspected to be melanomas. Clinically, these moles are large ( 6 mm in diameter), with an ill-defined, irregular border and irregularly distributed pigmentation (see photograph). It is estimated that 5–10% of the white population in the United States has one or more atypical nevi. Studies have defined an increased risk of melanoma in the following populations: patients with 50 or more nevi with one or more atypical moles and one mole at least 8 mm or larger, and patients with a few to many definitely atypical moles. These patients deserve education and regular (usually every 6–12 months) follow-up. Kindreds with familial melanoma (numerous atypical nevi and a strong family history) deserve even closer attention, as the risk of developing single or even multiple melanomas in these individuals approaches 50% by age 50.



anormal nevus

Congenital Nevi
The management of small congenital nevi—less than a few centimeters in diameter—is controversial. The vast majority will never become malignant, but some experts feel that the risk of melanoma in these lesions may be somewhat increased. Since 1% of whites are born with these lesions, management should be conservative and excision advised only for lesions in cosmetically nonsensitive areas where the patient cannot easily see the lesion and note any suspicious changes. Excision should be considered for congenital nevi whose contour (bumpiness, nodularity) or color (different shades) makes it difficult for examiners to note early signs of malignant change (see photograph). Giant congenital melanocytic nevi (> 5% body surface area [BSA]) are at greater risk for development of melanoma, and surgical removal in stages is often recommended (see photograph); (see photograph).



Blue Nevi


Blue nevi are small, slightly elevated, and blue-black lesions. They are common in persons of Asian descent, and an individual patient may have several of them. If present without change for many years, they may be considered benign, since malignant blue nevi are rare. However, blue-black papules and nodules that are new or growing must be evaluated to rule out nodular melanoma.
Freckles & Lentigines
Freckles (ephelides) and lentigines are flat brown spots (see photograph); (see photograph). Freckles first appear in young children, darken with ultraviolet exposure, and fade with cessation of sun exposure. In adults, depending on the fairness of the complexion, flat brown spots (lentigines), often with sharp borders, gradually appear in sun-exposed areas, particularly the dorsa of the hands. They do not fade with cessation of sun exposure. They should be evaluated like all pigmented lesions: If the pigmentation is homogeneous and they are symmetric and flat, they are most likely benign. Solar lentigines, also called liver spots, can be treated with topical 0.1% tretinoin, tazarotene 0.1%, 2% 4-hydroxyanisole with tretinoin 0.01% (Solage), laser therapy, and cryotherapy.



Seborrheic Keratoses


Seborrheic keratoses are benign plaques, beige to brown or even black, 3–20 mm in diameter, with a velvety or warty surface (see photograph). They appear to be stuck or pasted onto the skin. They are common—especially in the elderly—and may be mistaken for melanomas or other types of cutaneous neoplasms. Although they may be frozen with liquid nitrogen or curetted if they itch or are inflamed, no treatment is needed.


Seborrheic keratosis

Malignant Melanoma

Essentials of Diagnosis
  • May be flat or raised.
  • Should be suspected in any pigmented skin lesion with recent change in appearance.
  • Examination with good light may show varying colors, including red, white, black, and bluish.
  • Borders typically irregular

Malignant melanoma


General Considerations

Malignant melanoma is the leading cause of death due to skin disease. There were 55,000 cases of melanoma in the United States in 2004, with 7900 deaths. One in four cases of melanoma occur before the age of 40. Overall survival for melanomas in whites has risen from 60% in 1960–1963 to more than 85% currently, primarily due to earlier detection of lesions.

Tumor thickness is the single most important prognostic factor. Ten-year survival rates—related to thickness in millimeters—are as follows: < 1 mm, 95%; 1–2 mm, 80%; 2–4 mm, 55%; and > 4 mm, 30%. With lymph node involvement, the 5-year survival rate is 30%; with distant metastases, it is less than 10%. More accurate prognoses can be made on the basis of site, histologic features, and gender of the patient.

Clinical Findings

Primary malignant melanomas may be classified into various clinicohistologic types, including lentigo maligna melanoma (arising on chronically sun-exposed skin of older individuals); superficial spreading malignant melanoma (two-thirds of all melanomas arising on intermittently sun-exposed skin); nodular malignant melanoma, acral-lentiginous melanomas (arising on palms, soles, and nail beds); malignant melanomas on mucous membranes; and miscellaneous forms such as amelanotic (nonpigmented) melanoma and melanomas arising from blue nevi (rare) and congenital nevi 

Clinical features of pigmented lesions suspicious for melanoma are an irregular notched border where the pigment appears to be leaking into the normal surrounding skin; a topography that may be irregular, ie, partly raised and partly flat. Color variegation is present, and colors such as pink, blue, gray, white, and black are indications for referral. The American Cancer Society has proposed the mnemonic "ABCD = Asymmetry, Border irregularity, Color variegation, and Diameter greater than 6 mm" (see photograph). "E" for Evolution can be added. The history of a changing mole (evolution) is the single most important historical reason for close evaluation and possible referral. Bleeding and ulceration are ominous signs. A mole that stands out from the patient’s other moles deserves special scrutiny, "ugly duckling sign." A patient with a large number of moles is statistically at increased risk for melanoma and deserves careful and periodic examination, particularly if the lesions are atypical. Referral of suspicious pigmented lesions is always appropriate.
See Related Guideline from CURRENT Practice Guidelines in Primary Care 2007
While superficial spreading melanoma is largely a disease of whites, persons of other races are at risk for other types of melanoma, particularly acral lentiginous melanoma. These occur as dark, sometimes irregularly shaped lesions on the palms and soles and as new, often broad and solitary, darkly pigmented longitudinal streaks in the nails. Acral lentiginous melanoma may be a difficult diagnosis because benign pigmented lesions of the hands, feet, and nails occur commonly in more darkly pigmented persons and clinicians may hesitate to biopsy the palms, soles, and nail beds. As a result, the diagnosis is often delayed until the tumor has become clinically obvious and histologically thick. Clinicians should give special attention to new or changing lesions in these areas.

Dermoscopy—use of a special magnifying device to evaluate pigmented lesions—helps select suspicious lesions that require biopsy. In experienced hands, the specificity is 85% and the sensitivity 95%.

Treatment

Treatment of melanoma consists of excision. After histologic diagnosis, the area is usually reexcised with margins dictated by the thickness of the tumor. Thin low-risk and intermediate-risk tumors require only conservative margins of 1–3 cm. More specifically, surgical margins of 0.5 cm for melanoma in situ and 1 cm for lesions less than 1 mm in thickness are recommended.
Sentinel lymph node biopsy (selective lymphadenectomy) using preoperative lymphoscintigraphy and intraoperative lymphatic mapping is effective for staging melanoma patients with intermediate risk without clinical adenopathy and is recommended for all patients with lesions over 1 mm in thickness or with high-risk histologic features. a-Interferon and vaccine therapy may reduce recurrences in patients with high-risk melanomas. Referral of intermediate-risk and high-risk patients to centers with expertise in melanoma is strongly recommended.


Atopic Dermatitis (Eczema)

Essentials of Diagnosis
  • Pruritic, exudative, or lichenified eruption on face, neck, upper trunk, wrists, and hands and in the antecubital and popliteal folds (Figure 6–2: photograph).
  • Personal or family history of allergic manifestations (eg, asthma, allergic rhinitis, atopic dermatitis).
  • Tendency to recur. 


Eczema on eyelid


General Considerations


Atopic dermatitis looks different at different ages and in people of different races. Because most patients have scaly dry skin at some point, this disease is being discussed under scaly dermatoses. However, acute flares may present with red patches that are weepy, shiny, or lichenified (ie, thickened, with more prominent skin markings) and plaques and papules. Diagnostic criteria for atopic dermatitis must include pruritus, typical morphology and distribution (flexural lichenification in adults), and a tendency toward chronic or chronically relapsing dermatitis. Also helpful are (1) a personal or family history of atopic disease (asthma, allergic rhinitis, atopic dermatitis), (2) xerosis-ichthyosis, (3) facial pallor with infraorbital darkening, (4) elevated serum IgE, (5) fissures under the ear lobes, (6) a tendency toward nonspecific hand dermatitis, (7) a tendency toward repeated skin infections, and (8) nipple eczema.


Clinical Findings

Symptoms and Signs

Itching may be severe and prolonged. Rough, red plaques usually without the thick scale and discrete demarcation of psoriasis (see photograph) affect the face, neck, and upper trunk ("monk's cowl"). The flexural surfaces of elbows and knees are often involved. In chronic cases, the skin is dry, leathery, and lichenified (see photograph). Pigmented persons may have poorly demarcated hypopigmented patches (pityriasis alba) on the cheeks and extremities (see photograph). In black patients with severe disease, pigmentation may be lost in lichenified areas.


opic dermatitis (eczema).








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