Exam 2 - Dermatology (need to know) Flashcards
What is keratosis pilaris?
Common finding on the extensor aspects of extremities (posterior upper arms, anterior thighs), buttocks, and cheeks
What does keratosis pilaris look like?
“Chicken skin”
- Small bumps at the hair follicle (stratum corneum)
- Occasional diffuse eruption with small sterile pustules
Keratosis pilaris risk factors
- Children with atopic disorders
- Living in cold, dry climates
- Common in winter months
Keratosis pilaris management
- Mild cases
Lubricants and emollients to moisturize skin
Keratosis pilaris management for patients with (+) folliculitis
Antibiotics active against s. aureus
If patients would like topical treatment for keratosis pilaris, what can be prescribed?
Topical keratolytics combined with lactic acid 12%, salicylic acid, urea creams, retinoids, and lubricants applied several times a day
Keratosis pilaris patient education
Chronic condition but benign
- Treatment takes weeks to months and recurrence common
What is tinea pedis?
Athlete’s foot
- Superficial fungal skin infection found on the feet
What are the three clinical forms of tinea pedis (athlete’s foot)?
- Vesicles and erosions on instep of one or both feet
- Occasional fissure between toes with surrounding scale and erythema
- Rare diffuse scaling on weight bearing surface of foot with exaggerated scaling increases often extending to lateral foot margins
What organisms cause tinea pedis (athlete’s foot)?
T. rubrum, t. mentagrophytes
Tinea pedis (athlete’s foot) risk factors
Uncommon in preadolescence; more common in males
Tinea pedis (athlete’s foot) mode of transmission
Direct contact with contaminated surfaces (warm moist environment of showers and locker room floors)
- Often occurs with tinea cruris (jock itch)
Tinea pedis (athlete’s foot) HPI components
- Sweaty feet
- Use of nylon socks or non breathable shoes
- Exposure in family or at school
- Itching, intense burning, stinging, foul odor
- Microtrauma to feet
- Contact with damp areas
Tinea pedis (athlete’s foot) physical exam
- Red, scaly, cracked rash on soles or interdigital spaces (especially between third, fourth, fifth toes)
- Infection initially presents as white peeling lesions becoming erythematous, vesicular, macerated, fissured, scaly
- Dorsum of foot remains clear
Are diagnostic tests required for tinea pedis (athlete’s foot)?
If treatment failure or questionable diagnosis occurs
If diagnostic testing is indicated for tinea pedis, what tests/labs should be performed?
- KOH treated scrapings of border of lesion reveal hyphae and spores
- Wood’s lamp will fluoresce
- Fungal culture
Tinea pedis management
Antifungal medication (miconazole, clotrimazole) applied 1 cm beyond border of rash twice daily until 7 days after clearing
- Usual treatment is 3-6 weeks
What anatomic regions should class I and IV topical corticosteroids never be used?
Face, genitals, breasts, axillae
Class I topical corticosteroid examples
Superpotent
- Clobetasol propionate
- Betamethasone dipropionate
Class II topical corticosteroid examples
Potent
- Mometasone furoate
Class III topical corticosteroid examples
Upper mid-strength
- Fluticasone propionate
- Halcinonide
Class IV topical corticosteroid examples
Mid-strength
- Triamcinolone
Class V topical corticosteroid examples
Lower mid-strength
- Hydrocortisone valerate 0.2%
Class VI topical corticosteroid examples
Mild
- Desonide
Class VII topical corticosteroid examples
Least potent
- Hydrocortisone 2.5%, 1%, 0.5%
Topical corticosteroid adverse effects
- Hypo-pigmentation
- Striae
- Tissue atrophy
- Telangiectasia
Usual duration of therapy with high potency topical corticosteroids
<2 weeks
What is the most common type of eczema?
Atopic dermatitis
What is atopic dermatitis?
Pruritic inflammatory skin disorder characterized by exacerbations and remissions of dry and itchy red skin
Is atopic dermatitis associated with other atopy conditions?
Yes - asthma, allergic rhinitis, urticaria, acute reactions with food
Pathophysiology of atopic dermatitis
- Family or personal history of atopy
- Xerosis or dysfunction of skin barrier
- IgE reactivity
Atopic dermatitis clinical manifestation
Pruritic, erythematous, dry patches, often scaling, linear excoriations, crusting, oozing, well defined skin marking (lichenification)
Where does eczema present in infants?
Cheeks, scalp, forehead, extensor extremities
Where does eczema present in adults?
Face, neck, flexural folds, wrists, dorsal of feet
Non pharmacological treatment for eczema
- Wear soft cotton clothing
- Maintain cool temperature
- Use of cool mist humidifier
- Wash with mild detergents
- Moisturize (aquaphor)
- Hydration with tepid water bath
- Avoid known triggers
Pharmacologic treatment of eczema
- Mild to moderate topical corticosteroid (hydrocortisone 1%, triamcinolone 0.1%) to control inflammation
- Nonsteroidal topical calcineurin inhibitors (tacrolimus) - chronic moderate to severe eczema
- Antihistamines (benadryl, hydroxyzine) - control pruritus
- Loratidine (claritin) for daytime use
Bacteria that commonly causes superinfection with eczema
Group A beta hemolytic strep and staph
Treatment of superinfection with eczema
- Cephalexin (Keflex)
- Dilute bleach baths - quarter cup to half cup regular strength bleach per 1 full bathtub of water twice weekly
- Intranasal mupirocin
What is the most frequent contact dermatitis seen in children and one of the most common skin disorders in infants?
Diaper dermatitis
Diaper dermatitis clinical manifestation
- Chapped
- Shiny
- Erythematous
- Parchment-like skin with possible erosions on convex surfaces
- Creases spared
Candidiasis (in diaper area) clinical presentation
- Shallow pustules
- Fiery-red scaly plaques on convex surfaces, inguinal folds, labia, scrotum
Diaper dermatitis treatment
- Frequent diaper changes (q1-2h)
- Gentle cleansing
- Greasy lubricant
- Sitz bath, air dry
- Hydrocortisone 0.5-1% for inflammation
What is seborrheic dermatitis?
Chronic inflammatory dermatitis
- Infants - cradle cap
- Adolescence - dandruff
Seborrheic dermatitis clinical manifestation in infants
- Erythematous, flaky to thick crusts of yellow, greasy (waxy appearance) scales
- Mostly on scalp, but also face, behind ears, neck, trunk, diaper area
Seborrheic dermatitis clinical manifestation in adolescence
- Mild flakes with some erythema and yellow, greasy scales on scalp, forehead, nasal bridge, eyebrows
Is seborrheic dermatitis itchy?
Not pruritic and no pustules
Three main pharmacological agents used to treat seborrheic dermatitis
- Antifungals: -azoles
- Anti inflammatory: topical corticosteroids
- Keratolytic (remove excess scales): salicylic acid
Seborrheic dermatitis treatment in infants
Usually self-limiting in first year of life
- Mineral oil 5-10 minutes before shampooing
- Remove scales with toothbrush/soft brush
- Frequent washing with mild shampoo
Seborrheic dermatitis treatment in adolescence
Facial dermatitis - ketoconazole 2% topical, low potency topical corticosteroid
Scalp dermatitis - medicated shampoo (tar, ketoconazole, salicylic acid, selenium sulfide), topical corticosteroid
Rosacea risk factors
- Ages 30-50 years
- Females (but more severe in men)
Rosacea often coexists with ___ and can closely mimic it
Acne vulgaris
- Comedones do not occur with rosacea
What are the four types of rosacea?
- Erythematotelangiectatic
- Papulopustular
- Phymatous
- Ocular (medical emergency)
Pathophysiology of rosacea
Immune-mediated inflammation
Rosacea clinical manifestation
- Flushing
- Facial erythema
- Inflammatory papules and pustules
- Telangiectasia
- Edema
- Watery or irritated eyes
Erythematotelangiectatic and papulopustular rosacea treatment
Topical: metronidazole, azelaic acid, sulfacetamide/sulfur
Oral: doxycycline, tetracycline
Phymatous rosacea treatment
If mild, same as papulopustular (+ ivermectin)
If severe, refer to derm for laser, cryotherapy with isotretinoin, or topical tacrolimus
Non pharmacologic management of rosacea
- Mild emollient cleanser with light non greasy moisturizer
- Neutral pH facial cleanser
What is seborrheic keratosis?
Most common benign non-melanocytic skin lesion on the body
How does seborrheic keratosis present?
- Waxy or verrous appearing papules or plaques that have a “stuck on” appearance on the skin
- Varies in color
- Anywhere on body but spares palms and soles
Is treatment for seborrheic keratosis warranted?
Mostly for cosmetic reasons
- Cryotherapy
- Curettage
- Shave biopsy
Pathophysiology of herpes zoster (shingles)
Dermatologic eruption caused by reactivation of the varicella-zoster virus that follows, sometimes decades, a primary varicella zoster (chicken pox) infection
Herpes zoster (shingles) presentation
- Prodrome of pain, dysesthesia, pruritus
- Vesicular eruption in unilateral dermatomal distribution
- Pain (stabbing, burning, aching, excruciating); can progress to postherpetic neuralgia
Herpes zoster (shingles) risk factors
- Increasing age
- Immune suppression
Herpes zoster (shingles) transmission
- Contact
- Air
- Contagion possible once rash appears and continues until crusted over
Pharmacologic therapy of herpes zoster (shingles)
Antiviral therapy (-cyclovir) for 7-10 days within 72 hours of rash onset
Oral corticosteroids (prednisone) for pain
Preventative therapy of herpes zoster (shingles)
Shingrix for people >50 years old
Herpes zoster (shingles) patient education
- Keep rash dry and clean
- Avoid topical antibiotics, dressings with adhesives, clothing that may be irritative
Roseola transmission method
Respiratory droplets
Roseola infectivity period
From onset of exposure until 3 days after fever abates
Roseola incubation period
HHV-6 is 5-15 days, HHV-7 unknown
Roseola clinical presentation
- Primarily seen in infants
- Abrupt high fever 3-7 days that abates followed by abrupt onset of rash that begins at the trunk and spreads to extremities
- Spares the face
Roseola rash characteristics
Rose-pink maculopapular rash
Roseola treatment
- Acetaminophen (or NSAIDs if >6 months) for fever
- Adequate hydration
