Transcript Self-Treatment of Acne and General Skin Care

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
[email protected]
Lecture Overview
Skin Anatomy and Physiology
Acne
Dermatitis and Dry Skin
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).
The Skin
Three Layers
epidermis
dermis
hypodermis
Glands
sebaceous
sweat
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.
The Skin
Three Layers
epidermis
dermis
hypodermis
Glands
sebaceous
sweat
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.
The Skin
Three Layers
epidermis
dermis
hypodermis
Glands
sebaceous
sweat
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.
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 skin’s flexibility
and integrity.
When the skin’s 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.
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.
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.
Typical Distribution of
Pilosebaceous Units
Source: skincarephysicians.com
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.
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.
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.
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.
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.
Closed Comedones
(Whiteheads)
(L):skincarephysicians.com
(R): dermatlas.med.jhmi.edu
Open Comedones (Blackheads)
(L):dermatlas.med.jhmi.edu
(R):medlib.med.utah.edu/kw/derm
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.
Source:skincarephysicians.com
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
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
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
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 pimples—some
containing pus—appear 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.
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.
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.
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.
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.
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.
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.
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.
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 TriCyclen, 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.
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.
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.
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.
Retinoid-Induced
Teratogenicity
Retinoids Work by Initiating DNA
Transcription
Funny, He Doesn’t 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.”
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.
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.
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.
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 patient’s 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.
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, >
50% if both parents have atopic dermatitis.
Typically appears in the first year of life, as redness and
chapping of the infant’s 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.
Atopic Dermatitis
Source: dermatlas.med.jhmi.edu
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.
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.
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 welldefined, reflecting where contact with the substance occurred.
Contact Dermatitis from
Shoes
Source: dermatlas.med.jhmi.edu
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.
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.
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.
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.
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.
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.
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.
QUESTIONS?
[email protected]