Lecture 16: Dermatology I Flashcards
Skin physiology 3 functional regions
Epidermis
Dermis
Hypodermis
Epidermis
• Regulates water content of skin
• Controls drug transport into lower layers
-top of the skin
Dermis
• Nerve endings
• Vasculature
• Hair follicles
-2nd layer
Hypodermis
Provides nourishment and cushion
-3rd layer
Skin Care – Basic Care of Skin
- Avoid prolonged hot bathing/showering to prevent drying of skin
- After bathing or showering, the skin should be lightly towel dried (pat to dry, avoid rubbing or brisk drying)
- Use non-soap skin cleansers to avoid irritation/sensitivity
- Minimize the use of astringents and alcohol-containing cosmetics or cleansing products
Examples of low irritant products
Cetaphil Gentle Skin Cleanser, Free and Clear Liquid Cleanser, Dove, Neutrogena,
Ointment characteristics
Semi solid, water free (or nearly), greasy, sticky, protective, occlusive; can be difficult to spread
Hydration: Moisturizing and emollient propeties
Cream characteristics
Thicker than a lotion
thinner than an ointment
- more spreadable and less greasy than ointments
Hydration: Moisturizing and emollient properties
Lotion characteristics
Thinner than a cream, may contain oil and
water or alcohol; often provides cooling
effect
Hydration:Less hydrating than ointment of cream
Gel characteristics
Aqueous or alcoholic semisolid emulsion
Hydration: No emollient properties
Solution characteristics
Water or alcoholic lotion containing a dissolved powder
-Hydration: Tends to be drying
Wet or oozy
Consideration
Creams, lotions and pastes are most suitable
Dry and scaly
consideration
Ointments and oils are best
Inflamed
Consideration
Use wet compresses and soaks, then creams or ointments
Cracks and sores
Consideration
Avoid alcohol or acidic
preparations
Palms and soles
Consideration
Ointment or cream
Skin folds
Consideration
Cream or lotion
Hairy areas
Consideration
Lotion, solution, gel or foam
Mucosal surfaces
Consideration
Non-irritating formulations
Non-drug Topicals– Skin Protectants
Form a barrier on the skin to protect from moisture or irritants
• Lock in moisture
Examples of skin protectants
• Zinc oxide • Petrolatum • Calamine - Absorptive, antiseptic, and antipruritic properties • Dimethicone - Repels water and soothes inflammation
Non-drug Topicals – Moisturizers
Used to add moisture to the skin
Examples of moisturizers
- Aveeno Moisture Cream
- Cetaphil
- Neutrogena Hand Cream
- Vanicream
Non-drug Topicals - Emollients
Used to soften the skin
Examples of emollients
- Shea butter
- Cocoa butter
- Mineral oil
- Lanolin
- Beeswax
- Olive oil
Major mechanism of drug absorption
Passive diffusion through stratum corneum
Topical delivery of a drug from one of these vehicles depends on:
- Relationship between the drug and the vehicle
- Drug solubility in the vehicle
- Diffusion coefficient from vehicle
- Skin factors
Skin factors that affect drug absorption
Hydration
• Wounds/burns
• Inflammation/dermatitis
• Age – pediatric patients absorb greater proportion of drug than adults → Ratio of surface area to body weight is 2-3x
Hydrocortisone
OTC options are 1% or 0.5% = low potency steroid - Low risk of local and systemic effects • Safe short term • Skin atrophy is possible but rare • Caution face, eyelids, genitals Apply before moisturizers Avoid in children < 2 years of age DO NOT apply if skin in open or cracked
Hydrocortisone formulations
Ointment-Preferred on thick skin
Cream-less greasy, patients often prefer
Dermatologic Changes
- Macules
- Papules
- Nodules
- Vesicles and bullae
- Plaques
Macules
- Circumscribed, flat lesions
- Any shape or size
- Differ from surrounding skin in color
Papules
- Small, solid, elevated lesions
- Usually <1 cm in diameter
- The major portion of a papule projects above the plane of the surrounding skin
Nodules
- Palpable, solid, round, or ellipsoidal lesions
* Not a papule – deeper or more palpable
Vesicles and Bulla
- Technical terms for blisters
- Vesicles are circumscribed lesions that contain fluids
- Bullae are vesicles larger than 0.5 cm in diameter
Plaques
- Mesa-like elevation
* Occupy a relatively large surface area compared with height above the skin surface
Dermatitis
- Inflammation of the skin
Dermatoses
Skin disorder or disease
Xerosis
Dry Skin
Xerosis characteristics
Skins normally contains 10% to 20% water by weight
• If skin hydration drops below 10% the stratum corneum becomes brittle and may crack more easily
• Affects >50 % of older adults
Xerosis risk factors
- Environmental (i.e. hot showers)
- Dehydration
- Physical damage to skin
- Malnutrition
- Hypothyroidism
- Advanced age - epidermis thins over time
Xerosis Clinical Presentation
- Loss of moisture from skin à loss of elasticity à skin cracking
- Roughness
- Scaling
- Loss of flexibility
- Fissures
- Inflammation
- Pruritus
Moisturizing Skin
Moisturization = adding moisture + trapping moisture
• Baths are better than showers for moisturizing
• Moisturizers should be fragrance free
• There are no specific recommendations for quantity or frequency of moisturization
Moisturizer should be applied while
the skin is still moist or slightly damp (within 3 minutes of towel drying)
Xerosis Treatment
Nonpharmacologic therapy – moisturizing products
- Emollients
- Moisturizers
- Glycerin containing cleansers
- Bath oils
- Increased room humidity
- Hydration (oral)
Xerosis Treatment
Pharmacologic therapy
Topical hydrocortisone (OTC)
• Short-term use (< 7 days)
• Often does not respond well
• May reduce erythema and pruritus
Choosing a Moisturizing Product
- Lotions may be used on the scalp and other hairy areas and for mild dryness on the face, trunk and limbs
- Creams are more occlusive than lotions
- Ointments are the most occlusive and can be used for drier, thicker, or more scaly areas
Occlusive products are the best at moisturizing since
they capture trans-epidermal water loss by providing a layer of oil on the skin surface, increasing the moisture content of the stratum corneum
Combining multiple formulations can help
(cleanser + bath oil + emollient)
Atopic Dermatitis (AD)
Common inflammatory condition of the epidermis and dermis
• Affects children and adults
• Also known as atopic eczema
• 70% of AD cases have an atopic family history
• Characterized by episodic flares and periods of remission
Atopic Dermatitis (AD) Pathophysiology
- Inflammation with expression of cytokines and chemokines
* Decreased ability to retain moisture
Atopic Dermatitis (AD) Clinical presentation for children
- Often presents within first year of life
- Erythema, scaling on cheeks and folds
- Transitions to dry skin by age 2
Atopic Dermatitis (AD) clinical presentation for adults
- Often less severe plaque formation
- Erythema, scaly, exudative, lichenified
- Antecubital and popliteal fossae, hands, neck, forehead
- Pruritus
- Scratching and lichenification → excoriation
Atopic Dermatitis (AD) common triggers
- Food allergens (egg, milk, peanut, soy, wheat, nuts)
- Aeroallergens (dust mites, cat dander, mold, grass, ragweed, pollen)
- Stress
- Airborne irritants (tobacco smoke, air pollution)
- Cosmetics, fragrances
- Temperature extremes
- Electric blankets
- Excessive hand washing
- Soaps, detergents, scrubs
- Dyes or preservatives
Atopic Dermatitis (AD) Exclusions to self care
- Moderate-severe condition with intense pruritus
- Large area of body involvement
- <1 year of age
- Cutaneous infection
- Face or intertriginous areas
Atopic Dermatitis (AD) Goals
- Stop itch-scratch cycle
- Maintain skin hydration
- Avoid triggers
- Prevent infections
Atopic Dermatitis (AD) Strategy
- Identify and eliminate triggers
- Skin hydration/barrier protection
- Topical therapy (+/- systemic in refractory cases)
- Refer if symptoms worsen or do not resolve within 7 days
Atopic Dermatitis (AD) Non-Pharm management
- Avoid triggers
- Regular bathing
- Short time, lukewarm water, mild cleansers (ex. Cetaphil), moisturize after
- Avoid scratching
- Keep nails short and clean
- Cotton gloves at night
- Topical emollients/ointments
- Standard of care
- Maintain skin hydration
- Improves skin response rate in AD
- Apply at least twice daily
Atopic Dermatitis (AD) Pharm management
Hydrocortisone (HCT)
• Apply 1-2 times per day during flare-ups
• Refractory conditions should be referred for prescription agents
Atopic Dermatitis (AD) Diagnosis by clinical criteria
- Essential features = pruritus + eczema
* May have elevated IgE or eosinophils
Atopic Dermatitis (AD) Diagnosis by grading criteria
- Erythema
- Edema
- Papulation
- Excoriations
- Dryness
- Scaling and crusting
Atopic Dermatitis (AD) Diagnosis by atopic tria
- Asthma
- Allergic rhinitis
- Atopic dermatitis
Diaper Dermatitis
Acute inflammation of skin in perineum, buttocks, inner thighs, and abdomen
• Can occur in any population with incontinence
• Most common in infancy (thinner skin than adults)
Diaper Dermatitis Pathophysiology
- Skin compromise due to occlusion, moisture, microbes or friction
- Urine and feces break down skin
- Ammonia in urine raises skin pH which makes it more prone to breakdown
Diaper Dermatitis Clinical presentation
• Bight red, wet-looking patches and lesions
Diaper Dermatitis Exclusions to self-care
- Lesions present >/= 7 days or have not improved in 7 days despite treatment
- Secondary skin infection or symptoms of UTI
- Diaper dermatitis outside diaper region
- Presence of broken skin, including oozing, blood, or pus
- Chronic or frequently recurring lesions
- Systemic infection symptoms
- Behavioral changes
- Immunocompromised condition
Diaper Dermatitis goals
- Relieve symptoms
- Rid the patient of rash
- Discourage infection
- Prevent recurrences
Diaper Dermatitis Approach
- Determine whether self-care is appropriate
- Recommend OTC protectants for up to 7 days
- Refer if symptoms worsen or do not resolve within 7 days
Diaper Dermatitis Non-pharm treatment
- Increase diaper changes
- Gentle wiping with baby wipes
- Use of disposable diapers
- Prevention is key!
- Change diapers immediately
- Keep diaper area clean and dry
Diaper Dermatitis Non-pharm treatment pt 2
- Skin protectants - serve as a lubricant and physical barrier
- Topical talc and cornstarch powders
- Apply products liberally as needed
- Hydrocortisone is contraindicated!
Irritant Contact Dermatitis (ICD)
- Inflammatory skin reaction caused by an irritant
* Most cases related to occupation
Irritant Contact Dermatitis (ICD) Pathophysiology
- Often occurs on exposed skin surfaces
- Disruption of skin barrier
- Changes in epidermis
- Release of proinflammatory cytokines
- Many factors affect magnitude of skin response
- Existing skin conditions
- Quantity and concentration of substance
- Chemicals, acids, bases are more severe
- Contact time with irritant
Irritant Contact Dermatitis (ICD) Clinical presentation
- Symptoms are often delayed
- Inflammation and swelling
- Erythematous
- Itching and burning
- Dry, painful, cracked skin
- Generally resolves in several days after irritant removed
- Chronic exposure to irritant:
- Skin remains inflamed
- Fissures or scales may develop
- Skin may be hypo- or hyperpigmented
- Leathery thickening of skin
- Lichenification
Irritant Contact Dermatitis (ICD) Common substances associated with ICD
- Acids, alkalis
- Detergents, soaps, hand sanitizers
- Epoxy resin
- Ethylene oxide
- Fiberglass
- Flour
- Oils
- Oxidants, plasticizers and activators in athletic shoes
- Solvents
- Urine/feces
- Water
- Wood dust and products
Irritant Contact Dermatitis (ICD) Treatment goals and approach
• Remove the irritant
• Prevent further exposure to irritant
• Relieve inflammation, irritation and tenderness (non-pharm and pharm
options)
Irritant Contact Dermatitis (ICD)
● Avoid further irritant exposure ● Wash area of initial irritant exposure • Warm water and mild soap • Reduces contact time with irritant • Helps localize symptoms ● Protective clothing and equipment Skin protectants/ointments ● Colloidal oatmeal baths ● Topical corticosteroids - not recommended
Irritant Contact Dermatitis (ICD)- Wash area of initial irritant exposure
- Warm water and mild soap
- Reduces contact time with irritant
- Helps localize symptoms
Irritant Contact Dermatitis (ICD) Skin protectants/ointments Steps
Apply to the affected area
• Helps restore moisture to stratum corneum
• Protectant from further exposure
• Dimethicone containing products help repair epidermal barrier
ICD - Colloidal oatmeal baths
May help relieve itching
*Topical corticosteroids - not recommended
Allergic Contact Dermatitis (ACD)
Inflammatory dermal reaction after exposure to allergen
Allergic Contact Dermatitis (ACD) Common causes
- Poison ivy, oak, sumac
- Nickel (jewelry)
- Latex (gloves, healthcare workers)
- Cosmetics and fragrances
- Benzocaine
- Neomycin sulfate
Allergic Contact Dermatitis (ACD)- Urshiol induced ACD
Toxicodendron plants
• “Leaves of 3, let it be”
• Urushiol is the antigen released by direct damage to the plant
• Allergic response occurs within 10 minutes of contact
• Unwashed contaminated hands can transfer urushiol to other body surfaces and other individuals
• ~80% of those in the US are estimated to be sensitive to urushiol
• Reduced sensitivity in elderly
Allergic Contact Dermatitis (ACD) Clinical presentation
- Papules
- Small vesicles
- Pruritus
- Erythema (streaky/patchy)
- Inflammation
- Lichenification
- Affected area eventually crusts and dries
- Presentation varies based on severity
- Typically resolves in 10-21 days
Allergic Contact Dermatitis (ACD) Exclusions to self-care
- <2 years old
- ACD present >2 weeks
- Involvement of >20% of skin surface
- Extreme itching, irritation, or severe vesicle and bulla formation
- Swelling of the body or extremities
- Swollen eyes or eyelids swelling shut
- Discomfort in genitalia d/t itching, irritation, swelling
- Involvement/itching of the mucous members of the mouth, eyes, nose, anus
- Signs of infection
- Failure of self-care after 7 days
- Impairment of daily activities
Allergic Contact Dermatitis (ACD) Non-Pharm treatment
Education and prevention
- Protective clothing
- Barrier products block urushiol from absorbing into skin (IvyBlock- FDA approved)
- Plant eradication
- Urushiol is inactivated by wet conditions
- Remains active within dead plants or innate objects
- Cold showers with hypoallergenic cleansers
Allergic Contact Dermatitis (ACD) Non- Pharm Treatment
• Remove the known antigen ASAP
- May reduce chance and severity of reaction
- Wash are with soap and water (10 minutes)
- Nonprescription wash to prevent or relieve rash
- Zanfel
- Technu Outdoor Skin Cleanser
- Similar efficacy to soap – consider costs
Allergic Contact Dermatitis (ACD) Pathophysiology
- Allergen activates sensitized T cells after initial contact
- Next time allergen has contact:
- T cells migrate to site of contact
- Release inflammatory mediators
- Type IV delayed hypersensitivity reaction
- Cell-mediated immune reaction
- Can take 24 hours to 21 days to develop
- If previously sensitized → rash and symptoms usually develop 24-48 hours after exposure
Allergic Contact Dermatitis (ACD) Pharm treatment: Itching
Oral diphenhydramine (NOT topical)
Allergic Contact Dermatitis (ACD) Pharm treatment:Weeping
Astringents: Decrease edema and exudation • Aluminum acetate/Burrow’s solution • 1 tablet to 1 pint of water • Soak area 15-30 mins 2-4x day • Calamine lotion
Allergic Contact Dermatitis (ACD) Pharm treatment: Inflammation
- Hydrocortisone
- Most effective for mild-moderate ACD
- Cream preferred to ointment
- Allows weeping lesions to dry
Dandruff
Chronic, mildly inflammatory scalp disorder
Dandruff Clinical presentation
diffuse scaling at crown of
head +/- pruritus
Dandruff Pathophysiology
Hyperproliferative epidermal disorder
• Shedding of large, white scales
• Role of Malassezia yeast species?
Dandruff Treatment Goals
Reduce epidermal turnover rate
• Minimize cosmetic concerns
• Minimize itch
Dandruff Treatment Approach
• Regular non-medicated shampoo typical is sufficient for mild/moderate dandruff
• Nonprescription medicated shampoos suppress replication of Malassezia species
and reduce yeast count in the scalp and skin
• Refer to PCP if dandruff persists after 4-8 weeks with medicated shampoo
Dandruff Pharmacologic Treatment
Nonprescription medicated shampoos • Pyrithione zinc (Head and Shoulders shampoo) • Selenium sulfide (Selsun Blue) • Ketoconazole • Coal tar shampoo
Ketoconazole shampoo for dandruff
Anti-fungal shampoo with anti-Malassezia activity
Coal tar shampoo for dandruff
- Decrease rate of epidermal replication
- Second-line
- Limited efficacy
- Discolor light hair and clothing
• Shampoo Directions for dandruff
Wash hair and scalp daily or every other day for one week, then taper down
• Contact time is key to effectiveness
• Massage shampoo into scalp and leave for 3-5 minutes before rinsing
• Repeat rinsing to ensure residual is removed
Seborrheic Dermatitis
Inflammatory condition primarily near sebaceous gland
Seborrheic Dermatitis Pathophysiology
- Accelerated epidermal proliferation caused by elevated levels of Malassezia
- Epidermal cell turnover is 9-10 days compared to 25-30 days normally
Seborrheic Dermatitis Clincal presentation
- Dull, yellowish, oily, scaly areas on red skin
- Pruritus is common
- Common locations: Scalp, eyebrows, eyelids, cheeks, paranasal areas, beard area, sternum, central back, around ears, intertriginous areas
- Infantile form
- Cradle cap
- Usually clears without treatment by 8-12 months
- Adult stages
- Yellow, greasy scales on scalp to face
Seborrheic Dermatitis Treatment Goals
- Reduce inflammation and epidermal turnover
- Minimize or eliminate erythema, scaling, and pruritus
- Educate about chronic condition – control symptoms, not cure
Seborrheic Dermatitis Treatment Approach: Infants
Infants
• Usually self-limited with time
• Use non-medicated shampoos
• Gently massage scalp with baby
Seborrheic Dermatitis Treatment Approach: Adults
Shampooing is the foundation of treatment REGARDLESS of skin lesion location
• Medicated shampoos: Pyrithione zinc, Selenium sulfide, Ketoconazole
• Topical corticosteroids may be useful to treat inflammation in seborrheic dermatitis
• NOT typically useful in treating dandruff
• 7 day maximum use before refer
Psoriasis
Chronic inflammatory disease
• Plaque psoriasis most common
• Remissions and exacerbations are unpredictable
• Lesions may clear spontaneously
Psoriasis Pathophysiology
- Accelerated epidermal proliferation
- Excessive scaling on raised plaques
- Lesions may last a lifetime or disappear
- May leave skin hyper- or hypo-pigmented
Psoriasis Clinical Presentation
- Lesions start as small papules and unite to form plaques
- Well-circumscribed, sharply demarcated
- Overlying thick white scales
- Most common sites
- Exterior surfaces of elbows and knees
- Lumbar region of back
- Scalp
- Posterior auricular area
- Inflammation and itching
Psoriasis Triggers
- Environmental
- Physical, chemical
- Infections and immune status
- Certain drugs and corticosteroid withdrawal
- Ex: beta-blockers, lithium
- Psychological stress and hormones
- Obesity
- Use of alcohol and tobacco
Psoriasis Treatment Goals
- Control or eliminate signs/symptoms
* Prevent or minimize flare-ups
Psoriasis Treatment Approach
- Only mild cases can be self-treated
- Up to a few isolated lesions, no larger than a quarter
- Bathing will help remove loose scales which disrupts plaque formation
- Emollients to moisturize/soften skin
- Apply liberally with gentle rubbing 4x daily
- Hydrocortisone (OTC)
- Most effective for acute bright red flare lesions
- Refer to dermatologist for moderate to severe cases over large areas
Dermatoses Exclusions to Self Care
Less than 2 years of age
• Worsening or no improvement after 1-2 weeks of proper
use of OTC medication options
• >5% body surface area involvement for psoriasis
