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6. VITILIGO
1. CLINICAL MANIFESTATIONS
1. loss of melanin pigmentation
2. depigmentation first appears in areas of frequent injury - hands, knees, elbows
3. areas enlarge, merge - may go to total vitiligo
4. areas susceptible to injury by u.v. light
2. TREATMENT
1. Corticosteroids
1. Repigmentation - mechanism unknown
2. topical for isolated vitiligo
1. triamcinolone acetonide (0.1% cream)
2. total repigmentation in 20-30%
3. 4-6 months or longer
4. fluorinated steroids should not be used on face due to atrophy and telangiectasia
3. systemic
1. effective as topical
2. long term therapy
3. not recommended
2. Psoralens
1. 8-methoxypsoralen (methoxsalen) - OXSORALENR
2. trimethylpsoralen (trioxsalen) - TRISORALENR
3. activated by ultraviolet A - 320 - 400 nm
4. cause melanocyte hypertrophy, proliferation
5. increase melanosome transfer
6. melanocytes which survive in hair follicles, therefore no response in hairless areas or white hair
7. initial therapy followed by 2 hours of u.v. light
8. every other day treatment
9. increase dose or light exposure after every two treatments
10. 50-100 treatments over 6-12 months
11. methoxsalen - side effects - excessive burns, pruritus, edemabulae formation, nausea: long term - cataracts (ophthalmic exams, UVA absorbing glasses), premature aging, cancers
3. Depigmenting agents
1. in extensive vitiligo
2. 20% monobenzone (BENOQUINR) - topical to pigmented skin
3. twice daily, hypopigmentation 3 to 4 months, depigmentation - 1year

7. TOPICAL ANTI-INFECTIVES
1. PROPERTIES
1. Germicidal rather than germistatic activity.
2. High germicidal potency
3. Broad spectrum - at most sites do not have problems with superinfection
4. Rapid onset and sustained activity
5. Lipid solubility - favors germicidal activity
6. Dispersibility
7. Good therapeutic index
8. Germicidal kinetics important
9. Germicidal efficacy
2. TOPICAL GERMICIDES VS. SYSTEMIC ANTIBIOTICS
1. In most cases systemic antibiotics are superior in treatment of wounds and infections.
2. Intolerance to systemic drugs
3. Burns and superficial fungal infections
3. ANTISEPTICS
1. Principles of Use
1. applied topically to living tissue
2. destroy micro-organisms or inhibit their reproduction or metabolic activities
3. applied prophylactically by health care professionals
4. antimicrobial soap decreases skin bacteria for deodorant effect
5. skin cleansers and protectants for laity which contain antiseptics to
6. minimize potential for infection are of limited value - only adjuncts to removal of dirt and organic matter.
2. Drugs
1. Alcohols
1. ethanol, isopropanol
2. bactericidal due to rapid coagulation of proteins
3. 70% aqueous solution better than absolute - 70% kills 90% of cutaneous bacteria in 2 min.
4. isopropyl alcohol slightly greater bactericidal
5. activity - full strength or 70% aqueous
6. both are potent virucidal agents
7. not effective as fungicides or sporicides
2. Triclocarban - COASTR, DIALR, ZESTR
1. used in deodorant soaps only
2. ntibacterial and antifungal actions
3. limited to 1.5% concentration
3. Hydrogen Peroxide
1. decomposes to oxygen and water in wounds and on mucous membranes - no effect on intact skin
2. oxygen has little bactericidal effect but loosens masses of infected detritus in wounds
4. Chlorhexidine Gluconate - HIBICLENS‚ , HIBISTAT‚
1. broad spectrum of antimicrobial activity
2. most effective against gram-positive and gram-negative bacteria
3. rapid acting, considerable skin substantivity, low potential for contact sensitivity and poorly absorbed
5. Chlorine compounds, chlorophors
1. sodium hypochlorite, oxychlorosene
2. bactericidal, sporicidal, fungicidal, protozoacidal, virucidal
3. antiseptic, disinfectant, sterilant
4. 0.45 to 0.5% NaClO for surgical purposes
6. Iodine, Iodophors - BETADINER, PHARMADINER, others
1. iodine is bactericidal, sporicidal, fungicidal, protozoacidal, cysticidal and virucidal
2. valuable due to efficacy, economy and low toxicity
3. iodine tincture - 2% elemental iodine, 2.4% sodium iodine in water and 44-50% alcohol
4. povidone - iodine
0. free iodine released in solution
7. Phenolic Compounds - PHISOHEX‚ , LIFEBOUY‚ , IRISH SPRING‚ (with triclocarban)
1. hexachlorophene (PHISOHEX‚ ) - bacteriostatic - most effective against Gram-positive, little activity against gram-negative or spores
2. triclosan (deodorant soaps)
3. irritant and cutaneous absorption - some toxicity

 

4. TOPICAL ANTIBIOTICS
1. Principles
1. Group A beta-hemolytic Streptococcus and Staphylococcus aureus most common organisms
2. local cleansing with warm moist compress or soaks are useful; surgical incision and drainage or excision may be necessary
3. poorly absorbed topical antibiotics (bacitracin, gramicidin, neomycin and polymixin B) especially useful in limited pyodermas.
4. resistance by selecting out mutants
5. cultures inappropriate, Gram stain helpful
2. Bacitracin - generic, BACIGUENT‚ , mixtures
1. bactericidal against gram-positive
2. inactive against gram-negative
3. effective in primary pyodermas (superifical folliculitis, limited ecthyma, impetigo) and limited secondary pyodermas
4. used with systemic antibiotics
5. severe hypersensitivity reactions rare
6. may be used in pregnancy or lactation
3. Neomycin - generic, MYCIGUENTR, mixtures
1. aminoglycoside
2. too toxic for parenteral use, poorly absorbed orally
3. especially effective against staphylococci
4. used with systemic antibiotics
5. hypersensitivity reactions, especially in individual with contact dermititis or chronically damaged skin
4. Polymyxin B
1. not available alone - spectrum of action limited to gram-negative organisms including Pseudomonas
2. combined with other poorly absorbed antibiotic or corticosteroids
3. hypersensitivity most common adverse reaction although rare
5. Topical Antibiotics with Systemic Use
1. resistance after topical application
2. tetracyline, chlortetracyline, oxytetracyclin (with polymyxin B)
3. gentamicin - useful in Pseudomonas infections unresponsive to other topical antibiotics
4. erythromycin, tetracycline and clindamycin for acnes vulgaris
5. ANTIFUNGALS
1. Principles
1. mycoses classified as superficial, deep or systemic
2. Dermatophytosis (tinea) infections most common - involve skin, hair and nails caused by Epidermophyton, Trichophyton, and Microsporum
3. resistant fungi or involvment of hair or nails requires prolonged oral griseofulvin or ketoconazole
4. mild to moderate tinea - miconazole (14-28 days) or tioconazole - tolnaftate, compound undecylenic acid
1. also salicylic acid effective due to keratolytic effect
2. haloprogin when OTC medications inadequate moderately severe infections
3. topical clotrimazole, econazole, miconazole, sulconazole or ciclopirox
4. infections of palms, soles, and fingernails may require oral griseofulvin
5. tinea versicolor
1. selenium sulfide suspension - 15-30 min. daily for 7 to 14 days
2. sodium thiosulfate 25% with salicylic acid 1% also effective
3. zinc pyrithone shampoo
6. Superficial Candidiasis
1. responds to topical preparations of polyene antibiotics (amphoteracin B, nystatin)
2. imidazoles (clotrimazole, econazole, miconazole)
7. Imidazoles
1. clotrimazole - LOTRIMIN‚ , GYNE-LOTRIMIN‚ , MYCELEX‚ , MYCELEX-G‚
2. miconazole - MICATIN‚ , MONISTAT-DERM‚ , MONISTAT 7‚ , MONISTAT 3‚
3. ketoconazole - NIZORAL‚
4. interferes with biosynthesis of ergosterol
1. clotrimazole
1. useful for tinea versicolor, cutaneous candidiasis and candidal infections of mucous membranes and mucocutaneous junctions
2. two weeks to one month treatment
3. adverse reactions - erythema, stinging, blistering, peeling of skin, pruritis and uticaria
4. troche - nausea, vomiting, abdominal cramping, diarrhea
5. not contraindicated in pregnancy for vulvovaginal infections
2. miconazole
1. effective topically in dermatophytic infections and tinea versicolor, superficial cutaneous and vaginal candidal infections
2. side effects - irritation, burning or maceration
3. ketoconazole
1. adequate oral absorption
2. oral reserved for superficial cutaneous infections non-responsive to topical drugs or oral griseofulvin
8. Griseofulvin
1. derived from Penicillium
2. fungicidal to actively growing organisms, inhibits fungal mitosis orally active for tinea infections except tinea versicolor, drug of choice for tinea barbae and tinea capitis
3. minor reactions - headache most common, dryness of mouth, G.I.disturbance - occasionally blurred vision, syncope, photosensitivity, rash, insomnia
4. serious reactions - leukopenia, granulocytopenia, hepatotoxicity

 

9. Tolnaftate - AFTATER, TINACTINR, ZEASORB-AFR
1. used topically in treatment of tinea infections including tinea versicolor
2. well tolerated, sensitization rare
10. Compound Undecylenic Acid
1. effective topically for tinea infections except tinea versicolor
2. most extensively used for tina pedis (athlete's foot)
11. Polyene Antibiotics
1. amphotericin B - FUNGIZONER
1. topical application limited to treatment of cutaneous and some acute mucocutaneous candidal infections
2. not effective for tinea infections
3. local irritation reported
2. nystatin - MYCOSTATINR, NILSTATR, O-V STATINR
1. administered orally, vaginally or topically
2. not absorbed by GI tract
3. limited to infections of skin and mucous membranes caused by Candida
4. side effects infrequent, transitory - nausea, vomiting, diarrhea after oral administration

 

8. TOPICAL CORTICOSTEROIDS
1. ACTIONS
1. vasoconstriction decreases extravasation of serum,inhibits swelling
2. inhibits release of cytotoxic chemical that cause pain and pruritus
3. suppression of mitotic activity diminishes epidermal hyperplasia, may lead to atrophy with excessive use
4. limit inflammation and immune response
2. FACTORS IN CHOOSING DRUGS
1. inherent potency - high, intermediate or low
1. more potent fluorinated steroids necessary for less permeable areas
2. less potent steroids for more permeable areas and in maintenance therapy
3. hydrocortisone is steroid of choice in responsive conditions due to low expense and application to extensive areas for prolonged periods relatively safe
2. formulation and method of application affect degree of absorption - also character of lesion (acute, subacute, or chronic) - see lecture on Bases and Vehicles
3. age - young, especially infants, and elderly with atrophic skin may be more sensitive to steroids
3. ADVERSE REACTIONS
1. Related to inherent potency, concentration of drug, volume applied, skin condition, duration of use, site and area of application, use of occlusive vehicles or wraps
2. Local effects
1. epidermal and dermal atrophy resulting in thinning of the skin, striae, telangiectasia, and senile-type purpura are most common in highly absorptive areas
2. less common - rosacea-like dermatoses, perioral dermititis, acne, folliculitis and nonhealing leg ulcers - hypopigmentation
3. hypertrichosis with more potent steroids
4. rebound erythroderma or pustulation may occur on all body surfaces after more potent steroids are discontinued.
3. System toxicity
1. usually after high-potency corticosteroids applied to extensive areas under occlusive dressing for long periods