derm Flashcards
what is the structure and function of the skin?
Barrier against fluid loss Protection from ultraviolet radiation Thermoregulation Cushioning Immunologic protection Appearance
Define macule
flat (nonpalpable), < 1cm in size
What is a patch?
flat (nonpalpable), > 1cm in size
What is a papule?
raised, < 1cm in size
What is a plaque?
raised (a broad papule), > 1cm in size
What is a nodule?
similar to a papule but > 1cm and located in the dermis or subcutaneous fat
What is a vesicle?
fluid filled, < 1cm in size
What is a bullae
fluid filled, > 1cm in size
What is a wheal?
(hive) – edematous papule or plaque that usually lasts < 24 hours
What is a scale?
dry or greasy laminated masses of keratin
What is crust?
dried serum, pus, or blood
What is a fissure?
a linear cleft through the epidermis or into the dermis
What is erosion?
loss of all or portions of the epidermis alone, heals without scarring
What is an ulcer?
complete loss of the epidermis and some portion of the dermis, heals with scarring
What is nummular dermatitis (etiology, age peaks)
“coin-shaped”
Etiology: unknown - classified as a form of atopic derm
2 peaks of age distribution - most common 6th to 7th decade of life M>F peak in 2nd to 3rd decade of life F>M
What is nummular dermatitis (presentation)?
round-to-oval crusted or scaly erythematous plaques
Most common arms and legs
Start as papules which coalesce into plaques with scale
Early lesions may be studded with vesicles containing serous exudate
Usually very pruritic
Often recurs in the same locations as old lesions
Lesions often symmetrically distributed
Waxes and wanes with winter
What is nummular dermatitis (ddx and treatment)?
DDx: contact derm, psoriasis, CTCL, pityriasis rosea, tinea corporis
Treatment: topical steroids, moisturization
Discuss topical steroids, use, risks, and recommendations
may alternate high potency with mid potency to reduce risk or use on weekends only
Risks of overuse of topical steroids include: atrophy, striae, telangiectasias, hypopigmentation (temporary), can have systemic absorption if using long-term on a large body surface area
Should recommend <14/28 days , 2-3 x week, Sat/ Sun use
classes (7) based on vasoconstrictive properties (ointment stronger than cream)
What are topical calcineurin inhibitors, when are they used, and where?
Topical calcineurin inhibitors (steroid sparing agents)
Tacrolimus (Protopic) ointment
Pimecrolimus (Elidel) cream
Discuss class 1 steroids and examples
superpotent
Clobetasol propionate
Betamethasone dipropionate
for scalp, palms, soles
Discuss class 3 and 4 steroids and examples
mid-strength Fluocinonide Betamethasone valerate Triamcinolone trunk and extremities
Discuss class 6 and 7 steroids and examples
Class 6 and 7= low potency Fluocinolone Desonide Hydrocortisone face, genitals, intertriginous areas
Discuss allergic contact derm, common culprits, and etiology
Etiology: delayed type of induced sensitivity - cutaneous contact with a specific allergen to which the patient has developed a specific sensitivity
~25 chemicals are responsible for as many as one half of all cases
Common culprits: Poison ivy, topical antibiotics (e.g., Neosporin, neomycin, bacitracin), nickel, rubber gloves, hair dye, textiles, preservatives, fragrances, benzocaine
Discuss allergic contact derm presentation and DDx
Presentation: pruritic papules and vesicles on an erythematous base
Acute onset
Geometric morphology (circles, lines, etc)
Lichenified pruritic plaques may indicate chronic ACD
Initial site of dermatitis often provides best clue regarding the potential cause
DDx: drug rash, nummular dermatitis, seb derm, tinea, urticaria
Discuss allergic contact derm treatment
Treatment: avoid offending agent, topical steroids or calcineurin inhibitors, antihistamines, cool soaks, emollients, oral prednisone in severe cases, need to treat 14-21 days. can refer for patch testing to help determine allergen
Discuss drug eruptions common culprits and etiology
A drug-induced reaction should be considered in any patient who is taking medications and suddenly develops a symmetric cutaneous eruption (usually occurs w/in the first 2 wks of tx)
Common culprits: antimicrobial agents, NSAIDs, cytokines, chemotherapeutic agents, anticonvulsants, psychotropic agents
Discuss drug eruptions presentation and ddx
Presentation: Lesions usually appear proximally and generalize within 1-2 days
DDx: contact dermatitis, erythroderma, leukocytoclastic vasculitis, measles, pityriasis rosea, lichen planus, psoriasis (pustular), urticaria, syphilis
Discuss drug eruptions treatment
Treatment: discontinue offending agent
Can treat symptoms with antihistamines and topical steroids
Most drug eruptions are mild, self-limited, and usually resolve within 2 weeks of stopping the offending agent;
Note: some reactions can be life-threatening (SJS/TEN)
Discuss morbilliform drug reaction
most common form of drug reaction Primary Lesion Macules, papules Secondary Changes none Configuration coalescing Distribution Generalized Color Red
Discuss urticaria etiology and age range
Etiology: release of histamine & other vasoactive substances from mast cells & basophils
15-20% of the general population is affected at some point during their lifetime
May be acute (lasting < 6 wk) or chronic (lasting > 6 wk)
Can occur at any age, but chronic urticaria is more common in the 40s and 50s
Discuss acute urticaria
cause unknown in > 60% of cases; known causes include: infections (ask about recent illness and travel); caterpillars/moths; foods (e.g. shellfish, nuts); drugs (e.g. PCN, sulfonamides, salicylates, NSAIDs); environmental factors (e.g. pollens, chemicals, plants, danders, dust, mold); latex; exposure to undue skin pressure, cold, or heat; emotional stress; exercise
Discuss chronic urticaria
cause unknown in 80-90% of patients; known causes include all of the above as well as: autoimmune disorders; chronic medical illness; cold urticaria, cryoglobulinemia, or syphilis; mastocytosis; inherited autoinflammatory syndromes
Discuss urticaria presentation
Presentation: blanching, raised, palpable wheals
Occur on any skin area and are usually transient (last < 24 hrs) and migratory
Dermatographism may occur (urticaria resulting from light scratching)
What are s/s included with urticaria that should send someone to the ED?
Physical exam should focus on conditions that might precipitate urticaria or could be potentially life threatening – refer or send to ED if:
Angioedema of the lips, tongue, or larynx
Urticarial lesions that are painful, long lasting (> 36-48 hrs), ecchymotic, or leave residual hyperpigmentation upon resolution (suggests urticarial vasculitis)
Systemic signs or symptoms - arthralgias, arthritis, weight changes, lymphadenopathy, bone pain
Scleral icterus, hepatic enlargement, or tenderness that suggests hepatitis or cholestatic liver disease
Evidence on the skin of bacterial or fungal infection
Listen to the lungs for signs of asthma or pneumonia
Urticaria DDx and treatment
Treatment: H1 antihistamines (ie Benadryl, hydroxyzine, Zyrtec)
May add H2 antihistamines (ie ranitidine) for severe or persistent urticaria
Glucocorticosteroids for refractory cases
Zyrtec should be dosed bid; Doxepin, tricyclic antidepressants with potent antihistamine properties, or Xolair may be useful in chronic urticaria
Discuss seb derm etiology
Etiology: related to a pathologic overproduction of sebum; may involve an inflammatory reaction to the yeast Malassezia
Discuss Seb derm presentation and ddx
Presentation:
Erythema with greasy yellowish scale on the “T-zone” of the face, scalp, behind the ears, central chest , intertigo
Dandruff
Can affect intertriginous areas
Usual onset occurs with puberty
Worsens with changes in seasons, trauma, stress, Parkinson disease, AIDS, certain medications
DDx: Atopic or contact dermatitis, rosacea, perioral dermatitis, tinea, impetigo
Treatment for Seb Derm
Shampoo at least every other day (shampoos that contain salicylic acid, tar, selenium, sulfur, or zinc are especially helpful) – leave on for 5 minutes before washing off
Clobetasol 0.05% solution or Derma-Smoothe/FS (mineral/peanut oil + fluocinolone 0.1%) for severe flaking on the scalp
Ketoconazole 2% cream twice a day (for face, ears chest)
Hydrocortisone 2.5% cream – short-term use during flares
Tacrolimus ointment or pimecrolimus cream as steroid sparing agents
Etiology psoriasis
Etiology: Multifactorial disease that appears to be influenced by genetic and immune-mediated components
Psoriasis presentation and triggers
Presentation: Characterized by red papules and plaques with adherent silvery scale
Triggers: Physical trauma, stress, infection (Strep, HIV), pregnancy, medications
Drugs that can trigger psoriasis
NSAIDs Antibiotics Steroids Antimalarials Lithium ACE inhibitors Beta-blockers Calcium channel blockers Interferon Tetanus Antihistamines
What do do at each clinic visit for psoriasis?
Ask about joint pain 10% of patients have Psoriatic Arthritis (PsA) (Refer to Derm or Rheum) Estimate body surface area (BSA) An average palm = 1% Disease Severity: Mild <5% BSA Moderate = 5-10% BSA (Refer to Derm) Severe >=10% BSA (Refer to Derm) Note – psoriasis is associated with cardiovascular disease, smoking, alcohol, metabolic syndrome, lymphoma, depression, suicide
Describe psoriasis vulgaris and distribution
Chronic and stationary - lesions can persist for years Distribution: Elbows Knees Scalp Lumbosacral Umbilicus nail pitting and other nail changes are common
Describe Koebner’s phenomenon
Occurs in 20% of patients
Non-specific trauma can lead to formation of psoriasis in the area of irritation
Describe inverse psoriasis
Involvement limited to skin fold regions
Usually associated with minimal scaling
Distribution: axilla, inframammary region, genitocrural region, neck
Often confused with intertrigo
Describe topical treatment for psoriasis
Topical steroids
Hydrocortisone 2.5% ointment (low strength) – good for short term use on face, penis, and intertriginous areas
Triamcinolone 0.1% ointment (medium strength)
Clobetasol 0.05% ointment (high strength)
Synthetic Vitamin D
Dovonex (calcipotriene) cream – helps reduce scale
Topical calcineurin inhibitors – steroid sparing agents (good for face, penis, intertriginous areas
Protopic ointment
Elidel cream
Common treatment regimen
calcipotriene bid Mon-Fri and clobetasol oint bid Sat-Sun for lesions on trunk and extremities; hydrocortisone or calcineurin inhibitor for face, penis, and intertriginous areas
Describe etiology and prevalence of tidea pedis
Etiology: dermatophyte infection of the soles of the feet and interdigital spaces, commonly caused by Trichophyton rubrum
Prevalence increases with age; M > F
Describe tinea pedis presentation and ddx
Presentation: pruritic, scaling in a moccasin distribution, often with painful fissures between the toes
Can sometimes confirm diagnosis with KOH prep
DDx: contact dermatitis, dyshidrotic eczema, psoriasis
Describe treatment for tinea pedis
topical Azoles (ketoconazole) topical Allylamines (terbinafine) Castellani’s paint (especially good for the interdigital webspaces) Apply to bottoms, sides, and interdigital areas of the feet once or twice/day for at least 2 weeks, depending on which agent is used
Describe ochomycosis etiology, presentation, DDX
Etiology: a fungal infection of the toenails or fingernails
Presentation: asymptomatic subungual hyperkeratosis and onycholysis, usually yellow-white in color
Should confirm diagnosis before treating - clip nail to send for PAS or put in dermatophyte medium
DDx: Lichen planus, psoriasis, trauma
Describe onchomycosis treatment
Oral Terbinafine, itraconazole (6 weeks for fingernails; 12 weeks for toenails - check baseline Cr, LFTs, CBC and recheck if tx >6 weeks
If orals contraindicated (liver disease) may try ciclopirox lacquer or urea 40% with topical terbinafine but this is often not effective; Jublia is a new topical solution on the market (but treatment is 48 wks!)
Inform patients that it can take a year for the entire nail to grow out and appear normal; recurrence is common even after systemic treatment; clean shoes and use topicals as maintenance
Describe intertrigo etiology
Etiology: an inflammatory condition of skin folds resulting from heat, moisture, and friction
Often colonized by infection - usually candida but can also be bacterial, fungal, or viral
A common complication of obesity and diabetes
Describe intertrigo presentation, ddx
Presentation: Erythema, cracking, and maceration with burning and itching at sites in which skin surfaces are in close proximity (axillae, perineum, inframammary creases, abdominal folds, inguinal creases)
DDx: contact dermatitis, seborrheic dermatitis, cellulitis, inverse psoriasis, acanthuses nigricans
Describe intertrigo treatment
Treatment: Barrier creams such as zinc oxide paste, compresses with Burow solution 1:40 or dilute vinegar, absorbent powders and moisture-wicking undergarments, exposing the skin folds to air, topical antifungal agents for secondary infections (e.g., clotrimazole, econazole, ciclopirox, miconazole, ketoconazole, nystatin)
Describe scabies etiology, presentation, ddx
Etiology: Sarcoptes scabiei
In developed countries, scabies occur primarily in institutional settings and long-term care facilities; also common among children
Presentation: Extremely itchy, especially at night
Often involves armpits, groin, umbilicus, wrists, fingerwebs, nipples
Primary lesions typically include small papules, vesicles, & burrows
DDx: atopic dermatitis, bug bites, folliculitis, psoriasis
Describe scabies treatment
Treatment: topical antiscabietic agents (e.g., Permethrin 5%) are applied from the neck down with repeat application in 7 days, oral ivermectin is also effective Pruritus may continue for up to 2 weeks after successful treatment Antipruritic agents (e.g. sedating antihistamines) and/or antimicrobial agents (for secondary infection) may be needed All family members and close contacts must be evaluated and treated for scabies, even if they do not have symptoms * Itchy papules on the penis are scabies until proven otherwise
Describe zoster etiology
the reactivation of the varicella-zoster virus (VZV) in a dermatome
A person of any age with a prior varicella infection may develop zoster, but incidence increases with age due to declining immunity
Describe zoster presentation and DDx
Pre-eruptive phase: characterized by unusual skin sensations or pain within the affected dermatome that heralds the onset of lesions by 48-72 hours
Active eruptive phase: marked by lesions that begin as erythematous macules and quickly develop into vesicles; new lesions form over 3-5 days
Lesions in the eruptive phase tend to resolve over 10-15 days
Can be very painful and cause chronic neuralgia
DDx: poison ivy, atopic dermatitis
Describe zoster treatment
antivirals (e.g. acyclovir, valacyclovir, and famciclovir)
Patients are infectious until the lesions have dried
Zostavax for people ages 50 and older can help prevent zoster
Discuss herpes zoster ophthalmicus
important not to miss – involves the trigeminal (fifth cranial) nerve; vesicles may appear on the tip or side of the nose (Hutchinson sign) and urgent referral to ophthalmology is required
Discuss folliculitis etiology
primary inflammation of the hair follicle resulting from infections, follicular trauma or occlusion
Superficial folliculitis is common and often self-limited
Affects all races, ages, and men and women equally
Discuss folliculitis presentation and ddx
acute onset of erythematous, folliculocentric papules and pustules associated with pruritus or mild discomfort
DDx: Acne, contact dermatitis, milia, miliaria, insect bites
Discuss folliculitis treatment
uncomplicated superficial folliculitis can be treated with antibacterial soaps and good hand washing technique
refractory or deep lesions with a suspected infectious etiology may need empiric treatment with topical and/or oral antibiotics that cover gram-positive organisms (choose a drug that covers MRSA in areas of high prevalence or in predisposed patients)
mupirocin ointment in the nasal vestibule twice a day for 5 days may eliminate the S aureus carrier state in recurrent folliculitis
Discuss CA-MRSA prevalence
Prevalence: Studies have shown ~ 25-30% of the population is colonized with MSSA (usually on skin or in nasal passages)
A study in a California ED found 51% of patients presenting for evaluation of a skin infection had +MRSA cultures
Discuss CA-MRSA presentation and transmission
Presentation: infections usually manifest as folliculitis or a similar skin infection (patients often present with a “spider bite” or “infected pimple”)
Transmission of CA-MRSA is though an open wound or from contact with a CA-MRSA carrier
Discuss CA-MRSA treatment
I & D of the abscess and tx with appropriate antibiotics when indicated; wound exudates should be cultured to determine the causative organism and appropriate antibiotics
Oral antibiotics: Trimethoprim-sulfamethoxazole DS twice daily, w/ or w/o rifampin 600 mg/d; doxycycline 100 mg twice daily; clindamycin 450 mg 3 times a day (96% sensitive)
Discuss rosacea including etiology and ddx
Chronic inflammatory disease of the central face with 4 types:
Erythematotelangiectatic
Papulopustular
Phymatous (Glandular Rosacea)
Ocular
Etiology: unknown but vasculature, climatic exposures, chemicals and ingested agents, pilosebaceous unit abnormalities, microbial organisms, increased neoangiogenesis, and several other factors may play a role
More common in fair-skinned persons of European and Celtic origin
DDx: lupus, seborrheic dermatitis, perioral dermatitis
describe Erythematotelangiectatic Rosacea
History of flushing
Central facial erythema
Telangiectasias not essential
Describe Papulopustular Rosacea
Central facial erythema
Papules or pustules
Edema
Describe Phymatous Rosacea
Thickened edematous skin
Nose most commonly affected
Sebaceous hyperplasia
Describe Ocular Rosacea
Ocular symptoms occur prior to cutaneous manifestations in ~20% of patients
Blepharitis and conjunctivitis
Staph infections common
What are topical treatments for rosacea?
Sunscreen!!!!! A daily broad-spectrum sunscreen is recommended for all patients with rosacea Metronidazole Azelaic acid Sodium sulfacetamide/sulfur Protopic Erythromycin Clindamycin Tretinoin Benzoyl peroxide
Describe systemic treatments for rosacea
Tetracyclines DCN and MCN >> TCN Azithromycin Metronidazole Isotretinoin
What are key points when evaluating alopecia?
Detailed history, onset, stress, medications, diet , grooming , family history
Patchy or diffuse > 50% loss before noticeable
Scarring or non scarring
Loss of hair follicle openings
Scarring requires biopsy
Describe telogen effluvium
-stress, + hair pull test, > 25% telogen hair , non scarring, diffuse- consider Thyroid ds, drugs, nutrition (cbc, Tsh, iron, ferratin)
Describe androgenic alopecia
-family hx, non scarring, male pattern. Consider androgen excess in females
Describe trichotillomania
-emotional, broken hairs, non scarring, patchy. Dif: areata, fungal
Describe alopecia areata
-acute onset,smooth patches, autoimmune( DM, thyroid, vitiligo), exclamation point hairs, non scarring. Dif: tricho, fungal.
Topical steroids, ILK ,PUVA
Describe alopecia d/t SLE
Scarring or non scarring, other signs
steroids , hydroxychloroquine
Describe tinea capitis
Seborrea like, patchy , broken hair. Occipital lymph nodes.
Requires systemic, griseofulvin, terbinafine, itraconazole 1-3 months , follow LFTs
describe lichen planopillaris
F>M. pustular ,erythema localized
scarring
describe folliculitis decalvans
expanding patch with pustules to periphery
scarring
describe acne keloidalis nuchae
expanding patch with pustules to periphery to nape of neck
scarring
Describe bullous pemphigoid
Autoimmune blistering disease
Presence of circulating immunoglobulin G autoantibodies ( BP230, BP180)
Prodromal period : pruritus eczematous / urticarial lesions ( weeks to months)
Bullous phase abrupt onset widespread blister formation – tense, oval , round. Abdomen, flexor surfaces
Assess for ocular, mucosal involvement , genitalia, negative Nilolsky
Describe triggers for bullous pemphigoid
Pharmocologic : Lasix, phenacetin, enalapril , nsaids, vaccines, ampicillin, pcn, cephalexin
Traumatic : burns, radiation,
Infections: Human herpesvirus, Epstein barr , CMV, Hepatitis b and c
Differential Dx: contact, urticaria , bites, dermatitis
Describe treatment for bullous pemphigoid
Promote healing, reduce itching, prevent secondary infections
Topical steroids
Systemic oral steroids
Referral for biologic treatment :methotrexate, rituximab ,cellcept , azathioprine
