Self-Treatment of Acne, Dermatitis, and General Skin Care

1
Self-Treatment of Acne, Dermatitis, and General
Skin Care

• John Pedey-Braswell
• 2005 Pharm.D. Candidate
• University of Washington School of Pharmacy
• Pharmacy 301
• June 4, 2003

tafkab_at_u.washington.edu
2
Lecture Overview

• Skin Anatomy and Physiology
• Acne
• Dermatitis and Dry Skin

3
Skin Facts

• Largest Organ in the Body.
• Variable Thickness, averages about 1-2mm.
• Skin, Hair, and Nails serve as protective barrier
  between body and environment.
• Success of protection depends on age, immunologic
  status, underlying disease states, use of certain
  medications, and preservation of intact stratum
  corneum (outermost dead layer).

4
The Skin

• Three Layers
• epidermis
• dermis
• hypodermis
• Glands
• sebaceous
• sweat

5
Hypodermis

• Also known as subcutaneous tissue, is the
  innermost area of skin.
• Consists of loose connective tissue and adipose
  firmly anchored to the dermis above it.
• Varying thickness allows necessary pliability of
  human skin.
• Fatty component facilitates thermal control,
  holds food reserve, and provides cushioning or
  padding.

6
The Skin

• Three Layers
• epidermis
• dermis
• hypodermis
• Glands
• sebaceous
• sweat

7
Dermis

• Approximately 40 times thicker than the epidermis
  above.
• Consists of elastic and connective tissue
  (collagen and elastin) surrounded by a
  mucopolysaccharide substance.
• Fibroblasts, mast cells, nerves, blood supply.
• Sensation of itching arises in upper portion,
  stinging in middle region, pain in the lowest
  level.

8
The Skin

• Three Layers
• epidermis
• dermis
• hypodermis
• Glands
• sebaceous
• sweat

9
Epidermis

• Outermost layer consisting of compact, avascular
  stratified epitheal cells
• Five distinct layers (from bottom to top) strata
  germinativum, spinosum, granulosum, lucidum,
  corneum.
• Keratinocytes in the stratum germinativum divide
  and move upwards to the skin surface. In the
  process, they change from living cells to dead,
  thick-walled, flat, nonnucleated cells that
  contain keratin (a fibrous, insoluble protein).
• Melanin is produced in stratum spinosum.

10
Stratum Corneum

• Composed of flat, scaly, dead (keratinized)
  tissue.
• Outermost cells are flat plates that are
  constantly shed (desquamated) and replaced by new
  cells continually generated by mitotic processes
  in the basal cell layer.
• Complete cycle from basal cell formation to
  shedding is 28 to 45 days.
• Flexibility of this layer depends on its water
  content, which is normally 10-20 by weight.
  Influenced by humidity, temperature, surfactants,
  and trauma.
• Keratin can absorb many times its weight in
  water, and thus retains water to maintain the
  skins flexibility and integrity.
• When the skins water content drops below 10,
  chapping occurs and the stratum corneum becomes
  brittle and cracks easily allowing irritants
  and bacteria to penetrate more easily, leading to
  inflammation and possibly infection.

11
Acne vulgaris (common acne)

• Most common adolescent skin disorder, often
  linked to the onset of puberty.
• Approximately 85 of all people between ages
  12-24 years will develop it to some degree.
• Onset in males is typically between 16-18 years.
  Usually clears by the mid-20s.
• Female onset is usually 15-17 years.
  Unfortunately, may persist into 30s or 40s, and
  worsen in menopause.
• First lesions may precede other signs of puberty
  and diagnosed as early as age 7 years.
• Papular lesions generally appear during the
  mid-teen years, while nodular lesions appear in
  the late teens.

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Dermal Pilosebaceous Units

• Acne vulgaris has its origin in these units.
• Consist of a hair follicle and associated
  sebaceous glands.
• Connected to the skin surface by the infundibulum
  an epithelial tissue lined duct through which
  the hair shaft passes.
• Sebaceous glands produce sebum, which passes to
  skin surface through infundibulum then spreads
  over the skin to retard water loss and maintain
  hydration of skin and hair.
• Glands are more common on the face, back, and
  chest and so is acne.

13
Typical Distribution of Pilosebaceous Units

• Source skincarephysicians.com

14
Origins of Acne Vulgaris

• Production of androgenic hormones increases as a
  male or female approaches puberty. Precise cause
  of acne is not known, but believed to be linked
  to this increase and closely related to acne
  development.
• Androgenic hormones stimulate the sebaceous
  glands appearance of acne usually noticed at
  actual onset of puberty.
• Four processes linked to increase in androgens
  are closely related to acne development
• 1. Abnormal keratinization of cells in the
  infundibulum
• 2. Increase in sebum production
• 3. Accelerated growth in Propionibacterium acnes
• 4. Occurrence of inflammation.

15

16
A Zit is Born

• Abnormal keratinization of cells in the
  infundibulum leads to increased cohesiveness
  between the cells, and results in obstruction of
  the follicle rather than the removal of these
  cells to the skin surface.
• The trapped, keratinized cells plug and distend
  the follicle to form a microcomedo, the initial
  lesion of acne.
• As more cells and sebum accumulate, microcomedo
  enlarges and becomes visible as a closed comedo
  or whitehead. This is the precursor to other
  developing acne lesions.
• Hair in follicle can determine extent of comedo
  formation. Thin and small hairs can become
  trapped in the plug, while thick, heavier hairs
  (like on the scalp or in the beard) will push the
  plug to the surface, thus preventing comedo
  formation.

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More on Zit Formation

• Open comedones, or blackheads, occur when
  sufficient material accumulates behind the plug,
  and the orifice of the follicular canal becomes
  distended, allowing the plug to protrude. The
  tip of the plug of the open comedo may darken
  because of melanin content.
• Increase in circulating androgens stimulates the
  production of sebum, which is prevented from
  reaching the surface of the skin by the
  obstructing keratinized cells. At the same time
  the bacteria P.acnes undergoes accelerated
  growth.
• P.acnes is a major contributor to inflammatory
  acne lesions due to lipase production and
  breakdown of sebum to free fatty acids. Colony
  counts are higher in patients with acne than in
  those without it. Resulting inflammation causes
  localized tissue distruction.

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Inflammatory Acne

• Begins with closed comedones that distend the
  follicle, causing the cellular lining of the
  walls to spread and become thin.
• Primary inflammation of the follicle wall
  develops with the disruption of the epitheleal
  lining and lymphocyte infiltration.
• Severe inflammatory reaction follows if the
  follicle wall ruptures spontaneously or is
  ruptured by picking, squeezing, attempted
  extraction by dermatologist, or if contents are
  discharged into the surrounding tissue. May
  result in abscesses, which can cause scars or
  pits after healing.
• Pustules or purulent nodules are more likely to
  cause permanent scarring.

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A Picture is Worth a Thousand Words

• FIGURE 1. Stages of acne. (A) Normal follicle
  (B) open comedo (blackhead) (C) closed comedo
  (whitehead) (D) papule (E) pustule.
• Source American Academy of Family Physicians.

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Closed Comedones (Whiteheads)

• (L)skincarephysicians.com
  (R) dermatlas.med.jhmi.edu

21
Open Comedones (Blackheads)

• (L)dermatlas.med.jhmi.edu
  (R)medlib.med.utah.edu/kw/derm

22
Inflammatory Acne Papules

• A papule is defined as a small (5 millimeters or
  less), solid lesion slightly elevated above the
  surface of the skin. A group of very small
  papules and microcomedones may be almost
  invisible but have a "sandpaper" feel to the
  touch. A papule is caused by localized cellular
  reaction to the process of acne. This photo shows
  papules and comedones on the face of an acne
  patient.
• Sourceskincarephysicians.com

23
Inflammatory Acne Pustules

• A dome-shaped, fragile lesion containing pus that
  typically consists of a mixture of white blood
  cells, dead skin cells, and bacteria. A pustule
  that forms over a sebaceous follicle usually has
  a hair in the center. Acne pustules that heal
  without progressing to cystic form usually leave
  no scars. This photo shows pustules, papules and
  comedones on the face of an acne patient.
• Source skincarephysicians.com

24
Inflammatory Acne Macules

• A macule is the temporary red spot left by a
  healed acne lesion. It is flat, usually red or
  red-pink, with a well defined border. A macule
  may persist for days to weeks before
  disappearing. When a number of macules are
  present at one time they can contribute to the
  "inflamed face" appearance of acne. This photo
  shows the "red face" appearance of acne with
  macules.
• Source skincarephysicians.com

25
Inflammatory Acne Nodulocystic

• Like a papule, a nodule is a solid, dome-shaped
  or irregularly-shaped lesion. Unlike a papule, a
  nodule is characterized by inflammation, extends
  into deeper layers of the skin and may cause
  tissue destruction that results in scarring. A
  nodule may be very painful. Nodular acne is a
  severe form of acne that may not respond to
  therapies other than isotretinoin.
• A cyst is a sac-like lesion containing liquid or
  semi-liquid material consisting of white blood
  cells, dead cells, and bacteria. It is larger
  than a pustule, may be severely inflamed, extends
  into deeper layers of the skin, may be very
  painful, and can result in scarring. Cysts and
  nodules often occur together in a severe form of
  acne called nodulocystic. Systemic therapy with
  isotretinoin is sometimes the only effective
  treatment for nodulocystic acne.
• Source skincarephysicians.com

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What About Rosacea?

• Referred to as "adult acne," rosacea causes
  facial swelling and redness and therefore, is
  easy to confuse with other skin conditions, such
  as acne or sunburn.
• Those who have rosacea might first notice a
  tendency to flush or blush easily. The condition
  can occur over a long period of time and often
  progresses to a persistent redness, pimples and
  visible blood vessels in the center of the face
  that might eventually involve the cheeks,
  forehead, chin and nose. Other areas that can be
  affected by rosacea are the neck, ears, chest and
  back. Sometimes, rosacea affects the eyes.
• The pimples of rosacea, which often occur as the
  disease has progressed, are different than those
  of acne because blackheads and whiteheads rarely
  appear. Rather, people who have rosacea have
  visible small blood vessels and their
  pimplessome containing pusappear as small, red
  bumps.
• Rosacea can be controlled with medications and
  lifestyle changes. Early intervention by a
  dermatologist, the expert in skin, hair and nail
  conditions, is key to successful treatment. Delay
  in diagnosis and treatment because of
  non-physician treatments can result in scarring.

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Things Proven to Make Acne Worse

• Heredity chances of offspring developing acne
  are higher when both parents have had acne than
  when only one parent has the disorder.
• Skin Hydration decreases the size of the
  pilosebaceous duct orifice. Acne can be worsened
  by high humidity environments and tight-fitting
  clothing.
• Local irritation (acne mechanica) occlusive
  clothing, headbands, helmets, chin straps can
  aggravate acne.
• Exposure to dirt, vaporized cooking oils,
  industrial chemicals may cause occupational acne.
• Acne cosmetica is a mild form of acne on the
  face, cheek, and chin. Typically closed,
  noninflammatory comedones. Oil-based cosmetics,
  including shampoos, may be occlusive and plug the
  follicles, exacerbating or even initiating acne.

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Unsubstantiated Factors

• Chocolate
• Nuts
• Fats
• Colas
• Carbohydrates
• Sexual Activity acne begins at puberty and
  sexual activity may begin at the same time, but
  not a cause and effect relationship.

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Treatment Approaches

• Goals are to unblock pilosebaceous ducts and keep
  orifices open, plus avoiding factors that worsen
  acne.
• Talk with your pharmacist. Some medications such
  as corticosteroids (prednisone, et al) can cause
  acne. She, or he, can help with self-care
  product selection and provide feedback.
• Self-treatment is appropriate for
  mild-to-moderate noninflammatory acne (open or
  closed comedones).
• Do NOT add nonprescription medications to
  prescribed regimens unless recommended by
  prescriber.

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Proper Skin Cleansing

• Removing excess sebum from the skin in a program
  of daily washing produces a mild drying of the
  skin and, perhaps, mild erythema.
• Affected areas should be washed at least twice
  daily (more frequently if skin is oily) with warm
  water, medicated or unmedicated soap, and a soft
  washcloth then patted dry.
• Washing should not be excessively vigorous it
  should cause barely noticeable peeling that can
  loosen comedones
• Washing intensity and frequency should be reduced
  and a less drying soap considered if tautness
  occurs.
• Facial soaps that do not contain moisturizing
  oils are usually satisfactory. A certain degree
  of drying action is desirable, so facial soap
  should be tried before surfactant soap
  substitutes. Antibacterial soaps have no clinical
  value.
• Salicylic acid, sulfur, and resorcinol are safe
  and effective for treating acne, but their
  effectiveness as soaps is questionable because
  little, if any, residue is left on the skin after
  washing. Abrasive agents may be useful in
  treating noninflammatory acne, but avoid in
  inflammatory acne because of increased
  irritation.
• If inconvenient to wash during the day, cleansing
  pads can be used at school or work.

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Benzoyl Peroxide

• Available in diverse dosage forms such as
  lotions, gels, creams, cleansers, masks, and
  soaps.
• Different formulations are not equivalent the
  drying effect of the gel base is superior to a
  lotion or cream of the same strength (most gels
  are Rx only). Washes and cleansers are widely
  used as treatment adjuncts, but have little or no
  comedolytic effect.
• Causes irritation and desquamation that prevents
  closure of the pilosebaceous orifice.
• Irritant effect causes an increased turnover rate
  of epithelial cells lining the follicular duct,
  which increases sloughing and promotes resolution
  of the comedones. May take 4-6 weeks see full
  effect.
• Its oxidizing potential may contribute to
  antibacterial activity against P.acnes.
• AEs excessive dryness, peeling, skin sloughing,
  edema indicate that lower concentrations should
  be used for shorter periods of time. Can cause
  transient stinging or burning.
• May bleach hair or clothing.
• Avoid excessive exposure to sun or tanning beds
  may enhance the ability of UV rays to produce
  skin cancer.

32
Salicylic Acid/Sulfur/Resorcinol

• Salicylic acid is a mild comedolytic agent,
  available in nonprescription acne products.
• Acts as surface keratolytic, and enhances
  absorption of other agents.
• Considered adjunctive therapy, but cleansing pads
  are safe, effective, and superior to benzoyl
  peroxide in preventing and clearing both
  comedones and inflammatory lesions of acne.
• Precipitated, or colloidal, sulfur is in products
  as a keratolytic agent. Effective agent for
  resolving existing comedones, but continued use
  may have comedogenic effect.
• Noticeable odor and color makes sulfur products a
  tough sell for consumers.
• Resorcinol not recognized as safe and effective
  by the FDA, unless in combination with sulfur
  probably enhances keratolytic effect.

33
Prescription Remedies Antibiotics

• Used to control growth of bacteria
  Propionibacterium acnes in pilosebaceous ducts.
• Comedonal acne can usually be controlled with
  topical antibiotics such as clindamycin or
  erythromycin.
• Inflammatory acne often needs systemic antibiotic
  therapy with a tetracycline (tetracycline,
  doxycycline, or minocycline), erythromycin, or
  rarely ampicillin.

34
Prescription Remedies Hormonal

• Oral contraceptives may be useful adjunctive
  therapy for all types of acne in females.
• Sebum production is controlled by androgens, and
  oral contraceptives are known to reduce androgen
  levels by increasing sex hormone binding globulin
  levels reduces the availability of biologically
  active free androgens.
• Pills containing norgestimate or desogestrel
  (Ortho Tri-Cyclen, Ortho Cyclen, Desogen) appear
  to work best.
• Two to four monthes therapy may be required
  before improvement is seen, and relapses are
  common if medication is discontinued.
• The diuretic spironolactone is also used to
  control androgen levels.

35
Prescription Remedies Tretinoin

• Tretinoin (Retin-A) all-trans-retinoic acid.
• Used primarily in topical treatment of acne
  vulgaris when comedones, papules, and pustules
  predominate.
• Appears to stimulate mitosis and turnover of
  follicular epithelial cells and reduce their
  cohesiveness, facilitating extrusion of existing
  comedones and preventing formation of new ones.
  May take 6-8 weeks to see noticeable results.
• Skin irritant may cause transitory stinging and
  feeling of warmth. Normal use produces some
  erythema and peeling similar to that of a mild
  sunburn. Avoid contact with mucous membranes and
  eyes.
• Some patients will experience edema, blistering,
  and crusting of the skin. Photosensitivity may
  occur, as well as temporary hypo- or
  hyperpigmentation.
• Contraindicated in pregnancy, some case reports
  of congenital abnormalities. See isotretinoin.

36
Prescription Remedies tazorotene and adapalene

• Tazarotene (Tazorac) prodrug that is
  de-esterified in the skin to release active drug
  tazorotenic acid (a retinoid). Same action, AEs,
  contraindications as tretinoin.
• Available as 0.1 gel or cream.
• Adapalene (Differin) retinoid analog, a
  naphthoic acid derivative. Same action, AEs as
  tretinoin, HOWEVER no evidence that it is harmful
  to fetus.
• Available as 0.1 cream, solution, or gel.

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Prescription Remedies isotretinoin

• Isotretinoin (Accutane) 13-cis-retinoic acid.
  Generic version now available. 10mg, 20mg, 40mg
  capsules.
• Used in severe inflammatory acne after all other
  methods exhausted. Also used to treat some
  cancers.
• Probably works on similar transcription pathways
  as tretinoin. Dose-related reduction in sebum
  excretion, and subsequent decrease in P.acnes
  growth. Dosed by patient weight 0.5-2mg/kg.
• AEs dryness of mucous membranes and skin, with
  scaling, fragility, and erythema. Hair thinning.
  Increases serum triglycerides. Muscle and joint
  pain. Visual disturbances. Psychosis?
• Known teratogen and abortifacient. Prescribers
  must counsel patients of risks before
  prescribing. Females need negative pregnancy
  test, contraceptives starting one month prior to
  start of isotretinoin, and taken for one month
  after terminating drug. Prescriptions must have
  special sticker to be filled by pharmacist.

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Retinoid-Induced Teratogenicity
39
Retinoids Work by Initiating DNA Transcription
40
Funny, He Doesnt Look Like a Nazi

• Dr. Albert Kligman, University of Pennsylvania,
  Professor emeritus -- the father of
  retinoid-based acne treatments.
• Conducted experiments on prisoners at Holmesburg
  Prison (Phildelphia) between mid-50s to 1974.
• All I saw before me were acres of skin.

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Percutaneous Absorption of Drugs

• Drug must be released from its vehicle if it is
  to exert and effect at the desired site of
  activity.
• Release of drug occurs at interface between skin
  surface and applied layer of product.
• Many physical-chemical factors determine
  relationship between the rate of absorption and
  the amount of drug released.
• The degree of skin hydration and thickness of
  applied layer of drug are also important.
  Increased temperature at skin surface increases
  blood flow to the area, and enhances rate of
  percutaneous absorption.

42
Percutaneous Absorption of Drugs

• Oily bases such as petrolatum are transiently
  occlusive, promote hydration of the skin and
  generally increase molecular transport of drug.
  (ointments)
• Hydrous emulsions are less occlusive.
• Water-soluble bases (PEGs) are minimally
  occlusive, and may attract water from the stratum
  corneum and decrease drug transport. (solutions,
  gels, some creams)
• Powders with hydrophilic ingredients presumably
  decrease skin hydration because they promote
  evaporation from skin by absorbing available
  water.
• Stratum corneum provides the greatest resistance
  to drug absorption and is thought of as the
  rate-limiting step in percutaneous drug delivery.
  Molecular passage occurs mostly by passage
  diffusion.
• Hydration swells the stratum corneum, loosening
  its normally tight, densely packed arrangement,
  thus making diffusion easier.

43
Dermatitis and Dry Skin

• Dermatitis is a nonspecific term that describes a
  vast number of dermatological conditions that are
  inflammatory and generally characterized by
  erythema.
• The terms dermatitis and eczema are often used
  interchangeably to describe a group of
  inflammatory skin conditions of unknown cause.
• When the cause of a particular skin condition is
  known, the disorder is given a specific name.
  Known causes of dermatitis include allergens,
  irritants, and infections.
• Dry skin (xerosis) is a common occurrence is
  almost everyone. It may be seasonal in some, and
  chronic for others.
• Often not serious, but annoying and uncomfortable
  because of pruritis. Some may have pain and
  inflammation. Dry skin is more prone to
  bacterial invasion than normal skin.

44
Atopic Dermatitis

• Occurs most often in infants, children, and young
  adults. Most common dermatological condition
  seen in young children. In adults it is often
  associated with other skin conditions.
• Areas commonly affected (face, flexural areas on
  inside of knees and elbows, and collar area of
  neck) depend on the patients age.
• Atopy means not in the right place. No
  diagnostic lab tests exist, though there may be
  elevated IgE and eosinophil levels.
• May be accompanied by allergic respiratory
  disease, but atopic dermatitis is often the
  initial clinical manifestation of an allergic
  disease.

45
Atopic Dermatitis

• Common exacerbating factors include soaps,
  detergents, temperature changes, mold, dust,
  pollens, and emotional changes.
• Thought to be genetically linked. 25 risk if one
  parent has it, gt 50 if both parents have atopic
  dermatitis.
• Typically appears in the first year of life, as
  redness and chapping of the infants cheeks,
  which may continue to affect the face, neck, and
  trunk. May progress to become more generalized
  with crusting developing on the forehead or
  cheeks. Result of dried exudate containing
  proteinaceous and cellular debris from erosion or
  ulceration of primary skin lesions.
• Primary symptom is severely intense pruritic
  papules (solid, round, and elevated lesions less
  than 1cm in diameter).
• Affected skin can progress to erythematous,
  excoriated, and scaling lesions. After repeated
  scratching and itching, the skin becomes thick,
  or lichenified.

46
Atopic Dermatitis

• Source dermatlas.med.jhmi.edu

47
Treatment of Atopic Dermatitis

• Goals in treatment 1. Maintain skin hydration,
  2. Relieve or minimize symptoms of itching and
  weeping, 3. Avoid or minimize factors that
  trigger or aggravate the disorder.
• Skin hydration through use of emolients and
  moisturizers.
• Hydrocortisone can help prevent itching and
  weeping.
• See HCP if patient is less than 2 yr. old, or if
  condition is severe or involves large area of
  body.

48
Contact Dermatitis

• Refers to a rash that results from an allergen or
  irritant in contact with susceptible skin. Often
  the result of exposure to occupational irritants.
• Usually occurs in children over 8yr old.
• Irritant contact dermatitis is nonallergic and
  nonimmunologic reaction caused by exposure to
  irritating substances. Often occupation-related
  and commonly seen in patients who work in food,
  plastics, oil, agriculture, or construction
  industries.
• Irritant generally elicits a response on first
  exposure. Injury it causes to the skin may not
  be limited to erythema and vesiculation, but may
  result in ulceration and tissue necrosis. Mild
  irritants generally require repeated or extended
  contact to cause a significant inflammatory
  response.
• Acute irritation is more likely if the area is
  under occlusion, which minimizes evaporation and
  causes the skin to become more permeable to
  chemicals. Gloves, clothing, and diapers often
  increase susceptibility and should be changed
  often.

49
Contact Dermatitis

• Some agents may act as sensitizers iodine
  containing antiseptics, latex, formaldehyde,
  benzocaine, PABA, topical diphenhydramine
  (Benadryl).
• Allergic contact dermatitis is immunologically
  mediated and is manifested by a
  delayed-hypersensitivity reaction to contact
  allergens. Involves contact of the skin with an
  allergenic material acting as a hapten, which
  becomes attached to protein carriers on specific
  cells in the epidermis. Initial sensitizing
  exposure is necessary for the reaction to occur.
  On subsequent contact with the allergen, reactive
  skin areas typically present as eczema
  appearing within minutes to hours after exposure.
  Example poison ivy.
• Hands are most often involved in adults,
  particularly on the backs of the hands. Can
  occur on the upper back, thighs, axillary areas,
  feet, and face. Lesions are often asymmetric and
  well-defined, reflecting where contact with the
  substance occurred.

50
Contact Dermatitis from Shoes

• Source dermatlas.med.jhmi.edu

51
Treatment of Contact Dermatitis

• Decreasing exposure to irritants such as
  detergents, soaps, and solvents is a good
  preventative measure.
• Mild-to-moderate contact dermatitis usually
  amenable to treatment with nonprescription
  agents. Astringents such as aluminum acetate can
  dry lesions (Apply 20min, 4 times a day).
  Calamine and colloidal oatmeal can relieve
  itching. Hydrocortisone reduces erythema.
  Systemic antihistamines such as diphenhydramine
  and chlorpheniramine may relieve itching and help
  with sleep.
• Duration of therapy is usually short because the
  condition usually improves upon withdrawal of the
  allergen or irritant, typically within hours.

52
Products for Atopic Dermatitis, Contact
Dermatitis, and Dry Skin

• Bath oils consist of a mineral or vegetable oil,
  plus a surfactant. Mineral oil is better
  adsorbed on the skin than vegetable oil.
• Only minimally effective in improving dry skin
  because they are greatly diluted in water.
  Effect may be enhanced by adding oil at end of
  bath, and patting skin dry instead of rubbing it.
  
• Make tub and floor slippery, creating a safety
  hazzard especially for the elderlyor children.
• Make cleansing the skin with soaps more
  difficult.
• Colloidal oatmeal bath products (Aveeno) contain
  starch, protein, and a small amount of oil. Less
  effective at moisturizing than bath oils, but
  have antipruritic effect. May clog bath pipes if
  used on a regular basis.

53
Emollients/Moisturizers

• Most commonly used emollients include petrolatum
  and mineral oil. Attempt to formulate products
  that try to function like sebum. Sometimes try
  to use exotic oils to mimic lipid content, but
  petrolatum works best.
• Emollients are occlusive agents and moisturizers
  that are used to prevent or relieve the signs and
  symptoms of dry skin. Act by leaving an oily
  film behind on skin surface through which
  moisture can not readily escape.
• Some HCPs believe that emollients alone are not
  enough to maintain adequate skin hydration. A
  patient may be advised to hydrate the skin by
  soaking in water for 5-10 minutes, patting the
  skin dry, and applying an occlusive agent while
  the skin is still damp. Drinking plenty of water
  should also be stressed.

54
Humectants

• Humectants are hydrating agents that attract
  water. Often added to emollient base to draw
  water into the skin. Used alone they can
  evaporate water out of stratum corneum.
• Examples are glycerin, propylene glycol, and
  phospholipid products like lecithin.

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Keratin-Softening Agents

• Chemically alter the keratin layer to soften skin
  and cosmetically improve its appearance. Dry
  skin symptoms will not be improved without adding
  water to the stratum corneum.
• Urea in concentrations of 10-30 is mildly
  keratolytic and increases water uptake into the
  stratum corneum. Is able to remove crusted
  necrotic tissue at higher concentrations, however
  causes stinging, burning and irritation
  particularly on broken skin.
• Lactic acid is useful for treating dry skin at
  concentrations of 2-5. Increases hydration of
  human skin, and acts as a modulator of
  keratinization rather than a keratinolytic agent.
  Added to urea to stabilize effects on skin and
  for hydration.
• Allantoin is also a keratin softening agent,
  works by disrupting the structure. Generally
  less effective than urea for softening skin.

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Astringents

• Retard oozing, discharge, or bleeding of
  dermatitis when applied to unhealthy skin or
  mucous membranes. Work by coagulating proteins.
• When applied as a wet dressing or compress, they
  cool and dry the skin through evaporation. Act
  as vasoconstrictors and reduced blood flow to
  inflamed tissue, and cleanse the skin of
  exudates, crust, and debris. Have a low cell
  permeability so activity is limited to the cell
  surface and interstitial spaces.
• Examples are aluminum acetate and witch hazel.
  Patient may soak affected area in astringent
  solution two to four times daily for 15 to 30
  minutes.

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Topical Hydrocortisone

• Only corticosteroid available without a
  prescription for topical treatment of dermatitis.
  Available 0.5, 1 creams, ointments, sprays.
• Exact mechanism of action is unknown, it relieves
  redness, heat, pain, swelling, and itch
  associated with many dermatoses, possibly due to
  a vasoconstrictive effect.
• Apply sparingly to affected area three to four
  times a day. Make sure that infection is not
  present (bacterial or fungal), HC masks the signs
  of infection, allowing it to progress without
  patient knowing. Ask pharmacist if you are
  unsure.
• Do not use for prolonged periods of time.
  Response decreases over time, and skin atrophy
  may occur because of inhibited collagen
  production.

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QUESTIONS? tafkab_at_u.washington.edu