Dermatitis, Hair & Nails, Dermatophyte Infections Flashcards
What causes atopic dermatitis (eczema)?
heat
perspiration
allergens
contact irritants (wool, nickel, food)
What is the atopic triad?
eczema
allergic rhinitis
asthma
*Starts in childhood
What are the sx of atopic dermatitis (eczema)?
Hallmark = pruritus
- Acute lesions: Erythematous blisters/papules/plaques that crust over & become scales (MC in flexor creases)
- Nummular eczema: sharply defined discoid/ coin-shaped lesions (MC on dorsum of hands, feet, & extensors)
How do you manage ACUTE atopic dermatitis (eczema)?
topical corticosteroids, antihistamines for itching (diphenhydramine, hydroxyzine)
Wet dressings (Burrow’s solution). Abx if infection
What is an alternative tx for ACUTE atopic derm (eczema)? What is the benefit?
Topical calcineurin inhibitors (Tacrolimus, pimecrolimus) - inhibit cytokine synthesis
No skin atrophy like steroids
What are S/E of topical calcineurin inhibitors (Tacrolimus, pimecrolimus)?
Irritation
Lymphoma/skin CA risk
What are forms of health maintenance for atopic derm (eczema)?
Avoid triggers (soaps, detergents, frequent baths)
Maintain skin hydration w/ skin emollients (eucerin, aquaphor) & tepid baths
What causes contact dermatitis?
Irritants: chemicals, detergents, cleaners, acids, prolonged H2O, metals
What form of contact dermatitis is caused by prolonged exposure to urine/feces in infants?
Diaper rash
What are the sx of contact dermatitis?
Burning Itching Erythema Dry skin Eczematous eruption
How do you treat contact dermatitis?
Avoid irritants
Protective equipment
Wet dressings (Burrow’s solution)
Topical corticosteroids
How do you treat diaper rash?
Topical petroleum or zinc oxide
What causes dyshidrosis?
Sweating
Emotional stress
Warm/humid weather
Metals
What are s/s of dyshidrosis?
Pruritic “tapioca-like” tense vesicles on the soles, palms, & fingers (lateral digits)
How do you treat dyshidrosis?
Topical steroids *Ointments preferred
Cold compresses
Burrow’s sol
Tar soaks
What causes lichen simplex chronicus?
Repetitive rubbing/scratching
“itch-scratch” cycle
What are the s/s of lichen simplex chronicus?
Scaly, well-demarcated, rough hyperkeratotic plaques w/ exaggerated skin lines
How do you treat lichen simplex chronicus?
High dose topical steroids
Antihistamines
Occlusive dressings
What causes perioral dermatitis? What population is it most seen in?
Topical corticosteroid use
MC in young women
What are s/s of perioral dermatitis?
Papulopustules on an erythematous base
May become confluent into plaques w/ scales
May have satellite lesions
Spares the vermillion border
How do you treat perioral dermatitis?
Topical metronidazole or erythromycin
Oral tetracyclines
AVOID TOPICAL CORTICOSTEROIDS
What causes lichen planus? What condition increases incidence?
Idiopathic!
Hep C
What are the s/s of lichen planus?
5 Ps: Purple, Polygonal, Planar, Pruritic Papules w/ fine scales & irregular borders
Can develop Koebner’s phenomenon (new lesions at sites of trauma)
Wickham striae: Fine white lines on the skin lesions or oral mucosa.
Nail dystrophy
Where does lichen planus most commonly present on the body?
Flexor surfaces of the extremities, skin, mouth, scalp, genitals, nails & MMs
What is 1st line tx for lichen planus?
Topical corticosteroids
How do you treat the sx of lichen planus?
Antihistamines for pruritis, occlusive dressings
What is 2nd line tx for lichen planus?
PO steroids
UVB therapy
Retinoids (stimulate production of new cells)
What causes pityriasis rosea? Who is it most commonly seen in?
Uncertain etiology, a/w viral infections - HHV7
Older children & young adults
What can pityriasis rosea mimic? What seasons is it more commonly seen?
Syphilis!
Spring & fall
What are the s/s of pityriasis rosea?
Herald patch on the trunk
Salmon colored papules w/ white circular (collarette) scaling along cleavage lines in a Christmas tree pattern
What parts of the body is pityriasis rosea confined to?
Trunk & proximal extremities
How do you treat pityriasis rosea?
None needed
PO antihistamines, topical steroids, oatmeal baths for pruritus
UVB phototherapy if severe
What is alopecia areata? What causes it?
Nonscarring immune-mediated hair loss targeting the anagen hair follicles (scalp MC)
a/w other autoimmune disorders (thyroid, addison’s)
What are the s/s of alopecia areata?
Smooth discrete circular patches of complete hair loss that develops over weeks
Exclamation point hairs (tapering near the proximal hair shaft)
Nail abnormalities: pitting, fissuring, trachyonychia
What term is used for complete hair loss of the scalp & body (including eyelashes)?
Alopecia universalis
How do you treat alopecia areata?
If local –> intralesional corticosteroids
If extensive –> topical corticosteroids
What is androgenic alopecia? What causes it?
Progressive loss of the terminal hairs on the scalp
Dihydrotestosterone (DHT)
What are the s/s of androgenic alopecia?
Varying degrees of hair thinning & nonscarring hair loss (MC temporal/midfront/vertex of scalp)
How do you treat androgenic alopecia?
Minoxidil
Oral finasteride (5-alpha reductase inhibitor) - androgen inhibitor (inhibits conversion of testosterone to DHT)
What are the S/E of finasteride?
Decreased libido, sexual or ejaculatory dysfunction
What is psoriasis?
immune d/o w/ genetic predisposition
What are the s/s of “plaque” psoriasis?
MC type, MC on extensors
Raised, dark-red plaques/papules w/ thick silver/ white scales
Pruritus
Nail pitting. Oil spot
Auspitz sign (bleeding w/ removal of plaque)
Koebner’s phenomenon
What are s/s of “pustular” psoriasis?
Deep, yellow non-infected pustules –> red macules on palms/soles
What are s/s of “guttate” psoriasis?
Small, erythematous papules w/ fine scales, discrete lesions & confluent plaques
What are s/s of “inverse” psoriasis?
erythematous (no scale)
MC seen in body folds
What are s/s of “erythrodermic” psoriasis?
erythematous rash involving most of skin (worst type)
What are s/s of psoriatic arthritis?
Joint stiffness > 30 mins, relieved w/ activity
Sausage digits
Pencil in cup deformity on radiograph
How do you treat psoriasis?
Mild-Mod –> high dose topical steroids +/- Vit D (calcipotriene), topical tar, topical retinoids/vit A (Tazarotene)
Mod-severe –> phototherapy: UVB, PUVA &/or methotrexate, cyclosporine, retinoids (acitretin)
What causes seborrheic dermatitis? Who is this MC in?
Unclear
Hypersensitivity to Malassezia furfur may play role
MC in adult men
Where does seborrheic dermatitis occur? When does seborrheic derm worsen?
Areas of high sebaceous gland oversecretion (scalp, face, eyebrowns, body folds)
Stress & winter –> worsening sx
What are s/s of seborrheic derm in infants?
“Cradle Cap”: erythematous plaques w/ fine white scales
What are s/s of seborrheic derm in adults?
Erythematous plaques w/ fine white scales
When on scalp = dandruff
How do you treat seborrheic derm?
Selenium sulfide, sodium sulfacetamide, ketoconazole or steroids. Zinc pyrithione
Oral antifungals
How do you treat cradle cap?
Baby shampoo, ketoconazole, topical corticosteroids
What causes tinea versicolor?
Overgrowth of Malassezia furfur (yeast) - part of normal skin flora
What are the s/s of tinea versicolor?
hyper/hypopigmented, round/oval macules w/ fine scaling
Often coalesce into patches on trunk, face, extremities
Involved skin fails to tan w/ sun exposure
How do you diagnose tinea versicolor?
KOH prep: hyphae & spores “spaghetti & meatball”
Woods lamp: yellow green fluorescence
How do you treat tinea versicolor?
Topical antifungals: selenium sulfide, sodium sulfacetamide, zinc pyrithione, “azoles”
Itraconazole or fluconazole if widespread or failed topical tx
*Do not shower for 8-12 hrs after bc azoles are delivered to skin via sweat
What are s/s of tinea corporis?
Erythematous plaques (circular rash w/ clear center & defined borders), scaling, cracking, & vesicles
How do you distinguish tinea corporis from erythema migrans?
Presence of scales
How do you treat tinea corporis & tinea pedis?
Topical antifungal
PO griseofulvin if failed topical tx
What are the s/s of onychomycosis?
Opaque, thickened, discolored & cracked nails w/ subungual hyperkeratinization
MC = big toe!
How do you treat onychomycosis?
Itraconazole & terbinafine
What causes paronychia?
What is it? How does it occur?
Staph aureus MC, GABHS, Candida (if slow growing)
Infection of nail margin. MC occurs after skin trauma
What can a paronychia progress to?
A felon (closed-space infection of the fingertip pulp)
What are the s/s of a paronychia?
painful, red swollen area around the nail at the cuticle site
How do you treat paronychia?
Warm soaks, I&D
Cephalexin
Describe stasis dermatitis
See page 66-67 of PANCE Prep Pearls
Describe a Type I cutaneous drug eruption
IgE mediated
Urticaria, angioedema, immediate
Describe a Type II cutaneous drug eruption
Cytotoxic, Ab-mediated
Describe a Type III cutaneous drug eruption. Provide an example.
Immune antibody-antigen complex
Ex. drug-mediated vasculitis & serum sickness
Describe a Type IV cutaneous drug eruption
Delayed (cell-mediated) - morbiliform rxn
Ex. Erythema multiforme
Describe a nonimmunologic cutaneous drug eruption
Due to genetic incapability to detoxify meds (anticonvulsants & sulfas)
What are s/s of an exanthematous/morbiliform rash?
MC skin eruption
“Bright-red” macules & papules that coalesce to form plaques
Begins 2-14 days after med initiation
What are s/s of a urticarial drug eruption?
Occurs within mins to hrs after drug administration
MC triggers = abx, NSAIDs, opiates, contrast
What are s/s of erythema multiforme?
3rd MC drug eruption or caused by HSV
Target lesions, dull “dusty violet” red, purpuric macules/vesicles or bullae surrounded by red halo
MC meds: sulfas, PCNs, Phenytoin, Phenobarbital, dilantin
What other sx may accompany a drug eruption?
Fever, abd, or joint pain
How do you treat an exanthematous/morbiliform rash?
Oral antihistamines
How do you treat drug-induced urticaria/angioedema?
Systemic corticosteroids, antihistamines
How do you treat erythema multiforme minor?
Sx tx
How do you treat anaphylaxis?
IM epi = Tx of choice!
What is the difference btwn EM minor vs EM major?
Minor: No MM lesions
Major: involvement of ≥ 1 MMs, no epidermal detachment
How do you treat erythema multiforme major?
Symptomatic
Antihistamines, analgesics, skin care
Oral: Steroid/lidocaine/diphenhydramine mouthwash
If severe –> systemic steroids
