Ch. 17 Derm Flashcards
What do you call a Flat, nonpalpable, circumscribed lesion < 5 mm in diameter?
Macule
What do you call a Flat, nonpalpable, circumscribed lesion > 5 mm in diameter?
Patch
What do you call a Palpable, circumscribed lesion < 5 mm in diameter, raised above skin surface?
Papule
What do you call a Palpable lesion > 5 mm in diameter, raised above skin surface?
Plaque
What do you call a Firm lesion arising in subcutaneous tissue < 2 cm in diameter?
Nodule
What do you call a Firm lesion arising in subcutaneous tissue > 2 cm in diameter?
Tumor
What do you call a Raised, fluid-filled, superficial lesion < 5 mm in diameter?
Vesicle
What do you call a Raised, fluid-filled, superficial lesion > 5 mm in diameter?
Bulla
What do you call a Pus-filled superficial lesion < 5 mm in diameter?
Pustule
What do you call a Pus-filled lesion arising in subcutaneous tissue > 5 mm in diameter?
Abscess
What do you call a Evanescent, raised, round, or flat-topped lesion caused by edema?
Wheal
What is the difference between erythema multiforme minor and erythema multiforme major?
EM Minor - Rash without mucosal involvement
EM Major - Rash with mucosal involvement
Describe the rash of Erythema Multiforme.
Erythematous, papular rash that appears over 72 hours, most
commonly on palms and dorsal surface of forearms but also on feet, face,
and lower extremities, usually < 10% BSA.
■ Papules may evolve to target lesions with a characteristic central dusky or
purple zone surrounded by a pale ring and then third erythematous halo.
■ Lesions may have a vesicular or bullous appearance.
Migratory annular and polycyclic erythematous eruption, cutaneous manifestation of acute rheumatic fever.
Erythema marginatum
Expanding red lesion with central clearing at site of tick bite, Lyme disease.
Erythema migrans
Target lesions,
± mucosal involvement, many causes.
Erythema multiforme
Tender, raised red
nodules on legs, many causes.
Erythema nodosum
What is the treatment for Erythema Multiforme?
Symptomatic tx and topical steroids
If mucosal involvement –> oral prednisone +/- hospitlization if impaired oral intake
+/-antiviral prophylaxis to prevent recurrence
_____ and _____ are desquamating, erythematous rashes distinguished from each other only by extent of disease based on total body surface area (TBSA).
SJS and TEN
How does the total body surface area differ between SJS and TEN?
SJS involves < 10% TBSA and TEN > 30% TBSA (SJS/TEN overlap is in-between).
What is a significant risk factor for SJS&TEN?
HIV (1000x increased risk)
Is Nikolsky sign positive or negative in SJS/TENS?
Positive – Skin separates when gentle lateral pressure is applied
What is the treatment for SJS/TENS?
ICU or burn unit for skin care fluid/electrolyte correction
What is the mechanism of injury for Staphylococcal scalded skin syndrome (SSSS)?
Caused by an exotoxin produced by
S. aureus that is released into the bloodstream causing superficial separation of the skin and widespread painful erythema and blistering.
Describe the rash of Staphylococcal scalded skin syndrome (SSSS)
Sudden appearance of tender erythema with sandpaper-like texture prominent
in perioral, periorbital, and groin regions and in skin creases of the neck, axilla, popliteal, and antecubital regions;
- mucous membranes are not affected. (whereas SJS and TEN can both have mucosal involvement)
EXfoliative day begins on second day of illness
Is Nikolsky sign positive or negative in Staphylococcal scalded skin syndrome (SSSS)?
Nikolsky positive
What is the treatment for Staph Scalded Skin Syndrome?
■ Admission to ICU for fluid resuscitation, wound care and electrolyte correction
if extensive involvement.
■ Identify and treat source of staph infection with penicillinase-resistant
penicillins, such as oxacillin or vancomycin (depending on prevalence of community-acquired methicillin-resistant S. aureus).
■ Steroids are not recommended.
Exanthematous reactions are a type-____
immune reaction, appearing within 1-2 weeks after an offending drug is
taken for the first time, sooner in a sensitized individual. Antibiotics are a
common culprit.
IV
Describe the rash of exanthematous drug eruptions.
■ Widespread symmetric maculopapular eruption that resembles a viral
exanthem.
■ Pruritus is common while pain suggests a more serious problem such as SJS or TEN.
What is the treatment for exanthematous Drug eruptions?
■ Discontinuation of inciting agent
■ Symptom control with antihistamines, high potency topical corticosteroids,
Domeboro or Burow’s solution
What is the mechanism that causes urticaria?
due to activation of cutaneous mast cells with resultant mediator release
Describe urticaria appearance
Pruritic, erythematous plaques of varying size that are transient and migratory,
usually lasting < 24 hours.
What are signs/symptoms of Exfoliative Dermatitis (Erythroderma)?
■ Systemic complaints of pruritus, chills.
■ Presence of erythema and scaling involving > 90% of skin surface
Skin feels warm, leathery and indurated.
How is Exfoliative Dermatitis (Erythroderma) distinguished from
other desquamating diseases?
by a feeling of skin tightness, scaly skin, and large areas of involvement.
What is the treatment for Exfoliative Dermatitis (Erythroderma)?
■ Emergent dermatology consultation, hospital admission, correct hypothermia
and hypovolemia.
■ Identify and treat underlying cause.
■ Emollients, low-to-mid potency topical corticosteroids and oral antihistamines
are all useful therapies.
What can be a complication of Exfoliative Dermatitis (Erythroderma)?
■ Disruption of dermis can lead to water loss, excessive heat loss, and highoutput
congestive heart failure due to widespread vasodilatation.
■ Mortality is up to 30%.
What is the difference between a phototoxic eruption and a photoallergic eruption?
phototoxic eruption - Sunburn appearance on sun-exposed skin
photoallergic eruption - Eczematous reaction that is intensely pruritic on sun-exposed skin
Define a fixed drug reaction.
Sharply marginated oval or round
erythematous plaques that appear
and reappear at same site after repeat
exposure to same drug
Morbilliform rash that may become confluent, fever, malaise and lymphadenopathy; multiorgan involvement may occur; onset. 2-8 wk after drug exposure
Drug rash with eosinophilia
and systemic symptoms
(DRESS)
What is the treatment for Irritant Contact Dermatitis?
avoiding causative agent and using topical steroids and emollients.
What substance produced by poison ivy and poison oak causes allergic contact dermatitis?
Uroshiol
Uroshiol induces a type ___ hypersensitivity reaction
delayed Type IV hypersensitivity reaction
What is the treatment for allergic contact dermatitis?
■ Wash all contaminated skin and clothing immediately with soap and water
to eliminate urushiol.
■ Antihistamines and topical therapies (Burow’s solution, ultrapotent topical
steroids) are often needed.
■ Oral steroids are indicated in patients with severe reactions or those involving
face, axilla and groin. Taper over 2-3 weeks.
What is the treatment for Atopic Dermatitis (Eczema)?
■ Avoid skin irritants including perfumed soaps and detergents.
■ Warm baths followed by emollients
■ Topical corticosteroids for flares, consider antihistamines for severe pruritus
A chronic, immune-mediated skin disorder resulting in epidermal hyperplasia
and inflammation w/ Well-defined plaques of salmon-colored erythema with overlying silvery scale
Psoriasis
What are risk factors for psoriasis?
family history,
high body mass index,
smoking, and
alcohol consumption
What is first line treatment for mild to moderate psoriasis?
Topical corticosteroids and emollients
What is first line treatment for severe psoriasis?
Systemic treatment (methotrexate, retinoids, cyclosporins, biologics) and
ultraviolet therapy may be required for more extensive disease.
A superficial inflammatory process in areas with increased activity of sebaceous glands (scalp, ears, eyebrows, central face, upper trunk, intertriginous areas).
Seborrhea
What is the treatment of Cradle cap?
Reassurance, emollients, and frequent washing with mild shampoo
What is the treatment of seborrhea (adults and adolescents)?
Antifungal shampoo (eg, ketoconazole) or those with coal tar, sulfur, selenium
Topical corticosteroids can be used for more severe disease.
Superficial bacterial infection of the epidermis commonly around the nose
and mouth of children < 6 years with a second peak occurring in the elderly.
Impetigo
What are risk factors for impetigo (besides age)?
poor hygiene,
warm weather,
overcrowding, and
breaks in skin barrier from abrasions or insect bites
What are the two subtypes of impetigo?
Impetigo contagiosa
Bullous impetigo
What organisms cause impetigo contagiosa?
S. aureus and group A streptococci
What causes bullous impetigo?
Caused by epidermolytic, toxin-producing S. aureus
What is the treatment for impetigo with a limited number of lesions?
Topical mupirocin 2% ointment
What is the treatment for impetigo with extensive disease?
Oral antibiotic, such as dicloxacillin or cephalexin
Risk for MRSA: Trimethoprim/sulfamethoxazole or clindamycin; doxycycline for those > 8 years
Acute and rapidly progressive illness characterized by raised and intense
erythematous plaques with a sharply demarcated border and associated fevers/chills.
Erysipelas
What organism commonly causes erysipelas?
β-hemolytic streptococcus.
What is the treatment for erysipelas?
no systemic sx –> oral amoxicillin 5-10d
systemic sx –> admit + IV Ceftriaxone or Cefazolin
Which organisms are most commonly implicated in cellulitis?
S. aureus (including MRSA) and
Streptococcus pyogenes (group A streptococcus).
What is the treatment for simple nonpurulent cellulitis?
oral antibiotics, with return to ED if no improvement in 24 hours.
(MRSA coverage not recommended initially)
What is the treatment for purulent cellulitis?
cover for MRSA with clindamycin, doxycycline, trimethoprim sulfamethoxazole.
What is the treatment for Necrotizing Fasciitis?
Emergent surgical consultation when the diagnosis is suspected. Rapid surgical debridement is critical to control spread of infection.
ABx:
Carbapenem
OR
Vanc + Zosyn + Clindamycin
Ringworm-like configuration on the body with sharply marginated, annular lesions, raised or vesicular margins and central clearing
Tinea corporis
Scaling patch to scalp containing short, broken hairs (“black dots”) is most common form of tinea capitis in the United States; much more common in young children so consider alternative diagnosis in healthy adults
Tinea capitis
Tinea capitis with secondary immune response to fungus; appears
as an indurated, boggy plaque with overlying pustules
Kerion
How area tinea infections diagnosed/confirmed?
Confirmation by identification of branching hyphae in keratin scrapings after KOH prep
What is the treatment of tinea infections?
Topical antifungal agents are usually effective. Systemic therapy (griseofulvin,
itraconazole, or terbinafine) is required for infections of the hair and nails
and for recalcitrant disease.
How does the treatment of Kerion differ from other tinea infections?
treated the same as tinea capitis (oral antifungals) with the addition
of prednisone for 1-2 weeks
Superficial fungal infection caused by the yeast Malassezia; causes scaling plaques of various colors (pink, tan, white) usually on the chest and trunk
Tinea versicolor
How is tinea versicolor definitively diagnosed?
KOH prep
How is tinea versicolor treated?
topic antifungals (eg, ketoconazole shampoo) or oral itraconazole (extensive disease)
Immune-mediated disorder that presents with smooth and circular patches of hair loss; patches also contain short broken hairs, but these hairs narrow near base of shaft (exclamation point hairs).
Alopecia areata
Can present with areas of hair loss that appear patchy (“moth-eaten”)
Secondary syphilis
How is Herpes Simplex transmitted?
direct contact or infected secretions (saliva or genital)
HSV-__ primarily causes oral lesions throughout the mouth; after primary
infection a recurrence of lesions usually occur on the lower lip triggered
by local trauma, sunburn, or stress
HSV-1
HSV-__ mainly causes genital lesions.
HSV-2
How is HSV diagnosed?
Viral culture or PCR testing of mucocutaneous lesions
What is the treatment for HSV?
Oral acyclovir, famciclovir, and valacyclovir can shorten duration of symptoms.
A leading cause of corneal blindness
worldwide. It most commonly presents with a dendritic corneal ulcer.
HSV Keratitis
Painful skin and worsening rash in patient with baseline eczema; can be hard to differentiate from severe eczema in appearance
Eczema herpeticum
Fever, headache, and neurologic symptoms (altered mental status, seizures, deficits); predilection for temporal lobes; most
common cause of encephalitis
Herpes encephalitis
A primary or recurrent HSV-1 or HSV-2 infection of the finger causing painful vesicles on a digit that coalesce and may appear to contain pus, but instead contain necrotic epithelial cells.
Herpetic whitlow
What is the treatment for Shingles?
■ Antiviral therapy (acyclovir, famciclovir, valacyclovir) if within 72 hours of symptoms or if new lesions are still appearing
■ Pain control
Results from VZV reactivation in the trigeminal nerve first (ophthalmic) division with involvement of its nasociliary
branch.
Herpes zoster ophthalmicus
Results from reactivation of the VZV virus in the geniculate ganglion of the facial nerve with resultant inflammatory changes causing a polycranial neuropathy
Ramsay Hunt syndrome or herpes zoster oticus
How is Ramsay Hunt syndrome or herpes zoster oticus treated?
oral acyclovir and steroids
What is first line treatment for postherpetic neuralgia?
Tricyclic antidepressants
other tx include gabapentin, opiates, lidocaine patches
What is the medical term for lice infestation?
Pediculosis
What is the treatment for lice (pediculosis)?
Permethrin 1% rinse or 5% cream is first-line therapy.
What is first line treatment for scabies?
Permethrin, 5% cream
A second treatment should be done 7 days after the first to kill any nymphs that have hatched from eggs
Ivermectin, an oral antiparasitic, 200 mg/kg given on day 1 and then day 14 is a Centers for Disease Control recommended oral treatment option equivalent to permethrin in nonlactating, nonpregnant adults and in children > 15 kg.
All close contacts should be treated and linens washed and dried in a dryer on high heat.
Numerous, tender, erythematous subcutaneous nodules most commonly
on the pretibial area of the lower extremities; lesions may turn yellowpurple
and resemble bruises
Erythema Nodosum
What is the treatment for Erythema Nodosum?
■ Treat underlying cause.
■ Symptomatic treatment includes bed rest, leg elevation, and NSAIDs.
■ May take 6 weeks to 6 months for full recovery.
Multiple 1- to 2-cm diameter, salmon-colored oval plaques following the
ribs in a “Christmas tree” pattern on the trunk
Pityriasis Rosea
What is the treatment for pityriasis rosea?
■ Supportive, most do not require therapy.
■ May try antipruritics (eg, antihistamines, topical steroids). May be a role
for antibiotics, antiviral agents and phototherapy.
A life-threatening autoimmune disorder wherein loss of intraepithelial keratinocyte adhesion leads to extensive blistering of skin and mucous membranes and subsequent tissue loss.
Pemphigus Vulgaris
Is Nikolsky sign positive or negative in Pemphigus Vulgaris?
Positive
What is the treatment for pemphigus vulgaris?
■ Pain control, local wound care, antibiotics for secondary infection, and oral or IV steroids.
■ Admission for wound care and IV rehydration may be necessary in widespread disease.
Is Nikolsky sign positive or negative in Bullous Pemphigoid?
Negative (due to depth at which blisters form)
What is the treatment for Bullous Pemphigoid?
High-potency topical steroids and glucocorticoid sparing agents (Azathioprine,
mycophenolate, methotrexate, dapsone, tetracycline, and nicotinamide)
Describe a Stage 1 Pressure Ulcer.
Intact skin, local tissue erythema
Describe a Stage 2 Pressure Ulcer.
Penetrate the epidermis or dermis but not the subcutaneous tissue
Describe a Stage 3 Pressure Ulcer.
Extend through the dermis into the subcutaneous tissue
Describe a Stage 4 Pressure Ulcer.
Extend beyond the subcutaneous tissue through to the deep fascia and may involve muscle and bone
What is the most common form of skin cancer?
Basal Cell Carcinoma
Type of Basal Cell Carcinoma with Pearly papule with visible vessel enlarges over years to nodule with central ulcer.
Nodular Basal Cell Carcinoma
Type of Basal Cell Carcinoma that Resembles dermatitis, reddish patch with slight scale.
Superficial Basal Cell Carcinoma
Type of basal cell carcinoma that presents as a White, waxy papule or plaque.
Morpheaform Basal Cell Carcinoma
What is the treatment for Basal Cell Carcinoma?
Depending on stage, may require simple resection (surgical excision or Mohs
micrographic surgery) or addition of chemotherapy.
Kaposi Sarcoma is related to HHV-__ infection
8
What is the treatment for Kaposi Sarcoma?
■ Control of underlying HIV will often control the sarcoma as well.
■ Some patients require intralesion or systemic chemotherapy.
What is the most significant risk factor for melanoma?
primary relative with melanoma
