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Flashcards in Dermatology Deck (49)
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1
Q

Treatment for non-purulent cellulitis

A

PO:
dicloxacillin
cephalexin
clindamycin

IV:
cefazolin
naficillin
Clindamycin

2
Q

Treatment of purulent cellulitis

A
PO:
Clindamycin
TMP-SMX
Doxy
Linezolid

IV:
Vancomycin

3
Q

Treatment of skin abscess

A

I&D

Risk of endocarditis - IV vancomycin 1 g prior to I&D

PO: 
clindamycin
TMP-SMX
Doxycycline
Linezolid

IV: vancomycin

4
Q

Hidrandenitis suppurativa

A

chronic occlusion of apocrine glands - axila, groin, perineum

Tx:
avoid skin trauma, gentle cleansing, smoking cessation, wt loss

Mild: topical clindamycin, punch debridement
Severe - oral doxycycline or minocycline, more invasive surgical debridement

Alt: intralesional steroids, anti-adrenegic drugs, TNF-a inhibitors, oral retinoids

5
Q

Necrotizing fasciitis

A

Unexplained, excruciating pain in the absence of or beyond areas of cellulitis

Erythema with blister and bullae formation and possible crepitus

Perineal cellulitis with abrupt onset in rapid spread - Fournier gangrene

Most common underlying conditions:
DM
Alcoholism
Immunosuppression
Malignancy

Dx: surgical exploration
Rapidly worsening cellulitis with severe pain
crepitus - air on XR

Tx:
Immediate aggressive surgical debridement
Antibiotics:
Carbapenem (imipenem or meropenem) or beta-lactam plus beta-lactamase inhibitor (pip-tazo)
PLUS clindamycin
PLUS vancomycin

6
Q

Impetigo

A

MC: MSSA
MRSA
S. pyogenes

Papules -> vesicles with redness -> pustules -> yellow crust
MC on face

Tx:
mild - mupirocin

Mod-severe - dicloxacillin, cephalexin

MRSA:
Clindamycin
TMPSMX
doxy

7
Q

Acne medications known for causing photosensitivity

A

Tetracycline
Doxycycline
Tretinoin - topical

8
Q

Acne contributing factors and treatment approaches

A
  1. hyperkeratosis
    Retinoic acid
    - Tretinoin - topical
    - Isotretinoin - PO: risk hepatotoxicity, teratogenic, drying/cracking skin and lips; depression, SI; elevated TGs
  2. Sebum overproduction
    - Isotretinoin
    - Tretinoin
    - Spironolactone
    - OCPs
  3. Propionibacterium acnes proliferation
    -Erythromycin
    -tetracycline
    -doxycycline
    -minocycline
    Topical - clindamycin, benzoyl peroxide
  4. Inflammation
    - steroids sparingly, injected into lesion
    - can induce acne
9
Q

Rosacea

A

Middle aged patient
Facial erythema with telangectasias starting at the nose and cheeks
Recurrent facial flushing - hot/spicy foods, alcohol, temperature extremes, emotional reactions
Inflammatory papules, pustules, cysts, and/or nodules - similar to acne without comedones
Ocular blepharitis, conjunctivitis, and/or keratitis
Rhinophyma - sebaceous gland hyperplasia of the nose

Tx:
Topical:
Metronidazole
Azelaic acid

Systemic: - severe or unresponsive
Tetracycline, doxycycline or minocycline
Isotretinoin for refractory
Laser therapy for rhinophyma

10
Q

Herpes simplex virus

A

Latent in sensory ganglia
Primary infection - flu like illness

Eyes -> vision impairment
Esophagus -> odynophagia, dysphasia
Whitlow - fingers, cuticle area

Dx:
Tzanck smear - rules in
Viral cx
Serology - Ab

Disseminate with vertical transmission - severe neurological involvement - temporal lobe encephalitis

Tx:
Acyclovir
famciclovir
valacyclovir

11
Q

Varicella

A

Prodrome: malaise, fever, pharyngitis, headache, and myalgia for 24 hours prior to rash

Pruritic, evolving rash: red macules -> tear drop vesicles -> rupture and cresting over

  • vesicular rash starts on face and trunk then spreads to extremities
  • rash appears in successive crops of vesicles over 2-4 days
  • most lesions fully crusted by 6 days

Risk: skin bacterial superinfections - S. pyogenes
-adults made about pneumonia and/or encephalitis

Tx:
Antihistamines for pruritis
Cut fingernails- avoid excoriations
Acetaminophen for fever

Acyclovir: over 12 yo, hx of chronic cutaneous or CV disorders, on intermittent oral/inhales steroids, or taking chronic salicylates

Ppx: varicella vaccine at 1 yr, 4 yr

12
Q

Shingles

A

Reactivation of herpes zoster virus
Painful, group vesicles any dermatomal distribution
postherpetic neuralgia possible

Transmission through direct contact with active lesion

Vaccine ppx - not in pregnant or immunocompromised

Tx:
Uncomplicated, within 72 hrs of start of sxs:
-Valacyclovir
-Vamciclovir
-Acyclovir 

Analgesia with opioids

+/- prednisone if severe sxs and no contraindications

13
Q

Treatment of postherpetic neuralgia

A
gabapentin
pregabalin
TCAs
lidocaine patches
capsacin cream
14
Q

Treatment options for cutaneous warts

A

2/3 resolve spontaneously within two years

Salicylic acid - first line

Liquid nitrogen

5FU and imiquimod

curettage, trichloroacetic acid, cantharidin, surgical excision

15
Q

Molluscum contagiosum

A

mostly in children and patients with HIV
Pox Virus

Flesh colored lesions with central umbilication, shiny

Self-limited

Tx:
curettage
imiquimod
cryotherapy
laser therapy
16
Q

Tinea vesicolor

A

Malassezia furfur

Hyperpigmented or light brown/ pink macules often found on back and shoulders

Hyphae and spores - spaghetti and meatballs

Tx:
Ketoconazole 2% shampoo
Topical antifungal - terbinafine
Selenium sulfide
Oral antifungal for extensive disease - ketoconazole, fluconazole, itraconazole
17
Q

Tinea

A

Differentiated by location - capitis (scalp), corporis (body), cruris (groin), pedis (foot), unguium (nails)

Microsporum, Trichophyton, Epidermophyton

pruritic, erythematous, blisters, scaly plaques, Central clearing

Tx:
Skin:
topical - clotrimazole, terbinafine, nystatin
oral - terbinafine, itraconazole, fluconazole

Scalp: oral - griseofulvin (first line), terbinafine, itraconazole, fluconazole

nails:
Oral - terbinafine, itraconazole, fluconazole - 6 weeks for finger, 12 weeks for toe - check LFTs before starting
Topical - ciclopirox, efinaconazole

18
Q

Intertrigo

A

candida albicans
Skin creases - satellite lesions

KOH - pseudohyphae

Tx: topical clotrimazole or terbinafine

(contact derm - no folds, no satellites)

19
Q

Scabies

A

severe pruritis with burrows and papules located on extremities in and between fingers and toes - worse after hot bath

Skin scrapings will show mites, eggs

Tx: permethrin cream
Oral - ivermectin

20
Q

Pediculosis capitis

A

pruritus

Tx: permethrin cream or shampoo - rinse out after 10 min, then comb out lice and nits

Alt: topical malathion or ivermectin

21
Q

Pediculosis corporis

A

pruritis

Tx: permetherine cream and leave on for 8-10 hrs

22
Q

Pediculosis pubis

A

tx with permetherine or pyrethrin cream - rinse out after 10 min then comb

alt: topical malathion and ivermectin

23
Q

Erythema multiforme

A

IgM immune complex deposition

Features:
Skin lesion with target appearance - dull red center, pale zone, and darker outer ring
-can involve palms and soles
many different shapes
Develop over 10+ days: macule -> papule -> vesicles/bullae in the center of the papule

Common sites: hands/forearms, soles/feet, face, elbows and knees, penis and vulva

Severe form invovles mucous membranes -> SJS/TEN

Tx:
stop inciting medication
Symptomatic treatment with antipuritics
If severe -> systemic glucocorticoids
HSV hx - acyclovir or valacyclovir
24
Q

Drugs/other causing erythema multiforme

A
PCN
sulfonamides
NSAIDs
OCPs
Anticonvulsant meds
HSV
Mycoplasma pneumoniae
25
Q

Stevens Johnson sn vs Toxic epidermal necrolysis

A

SJS - less severe
-skin sloughing - epidermal detachment limited to less than 10% of body surface area

TEN - at least 30% skin detaching

Always involves mucous membranes

labs:
low H&H
elevated AST, ALT

Tx:
Stop offending agent
Corticosteroids
Analgesia
IVF
Burn unit Admit
Acyclovir if HSV hx
26
Q

Seborrheic dermatitis

A

Chronic relapsing dermatitis associated with sebaceous glands
-can be caused by Malassezia furfur

Erythematous plants with greasy looking yellowish scales

Tx:
Scalp: medicated shampoo - ketoconazole, selenium sulfide, ciclopirox
Alt - tar containing shampoo

Skin: low potency topical steroids or topical antifungal Cream - ketoconazole

27
Q

Seborrheic keratosis

A

Noncancerous skin growth that originates in keratinocytes
Various presentations: flat, raised, tan colored, warty, “pasted on” appearance

No treatment needed

28
Q

Atopic dermatitis (eczema) treatment

A

Skin hydration: emollients - petroleum jelly or other low water content creams

Topical steroids

Calcineurin inhibitiors - tacrolimus or pimecrolimus

Severe or resistant cases - UV light therapy, systemic steroids, immunosuppresants - methotrexate, cyclosporine, azathioprine

Abx for open lesions - cover S. aureus and Strep spp.

29
Q

Psoriasis

A

Extensor surfaces
Bleed when scale removed - Auspitz sign

Bx: thickened epidermis, absent granular layer, nucleated cells in stratum corneum
20% with arthritis

Tx:
Mild to mod:
Topical steroids and emollients
Alts: tar based products, topical retinoids (tazarotene), topical vitamin D (calcipotriene), anthralin, calcineurin inhibitors - tacrolimus, pimecrolimus

Severe:
Photo therapy
Oral retinoids
Immunosuppressants - methotrexate, cyclosporine
Adalimumab, etanercept, infliximab
30
Q

Pityriasis rosea

A

Papular lesions on trunk and extremities in Christmas tree pattern
Herald patch 2-5 cm

Tx:
Self-limited 4-6 weeks
Mod - potency topical steroids for pruritis
Severe - UV therapy, acyclovir, erythromycin

31
Q

Erythema nodosum

A

Inflammation of the subcutaneous fat septa
Painful erythematous nodules - anterior tibia, trunk
Delayed immuno rxn to infection, vascular dz, drugs

Accompanied with malaise, arthralgias, fever

Labs: + ASO, elevated ESR
Bx - fatty inflammation

Tx:
self limited
NSAIDs
Potassium iodine
Corticosteroids
Causes:  SPUDBITS
Strep
Pregnancy
Unknown
Drugs
Behcet dz
IBD
TB
Sarcoidosis
32
Q

Lichen planus

A

Young - assoc HIV; older - Hep C

Skin: pruritic, purple, polygonal papules and plaques - shiny and flat, common on flexor surface of extremities (wrist)

Wickham’s striae - white, lace-like pattern on surface of papules/plaques

Mucous membrane: Wickham’s striae in lateral buccal mucosa and possible erosive lesions may be come infected with Candida

Genital involvement - limited to violaceous papules on glans penis and vulva

Tx:
corticosteroids - medium to high potency - topical, interlesional, oral if topical unsuccessful
Acitretin - oral retinoid

33
Q

Stages of decubitus ulcers

A

Stage 1: pressure related alteration in intact skin - change in color, consistency, sensation or temperature

Stage 2: superficial ulcer, abrasion, or shallow crater

Stage 3: Full thickness skin loss with damage to the subcutaneous tissues - deep crater

Stage 4: extensive destruction or necrosis; damage to muscle, bone or supporting structures

34
Q

Stasis dermatitis

A

eczematous dermatitis with inflammatory papules, scaly and crusted erosions, increased pigmentation, stippling with recent and old hemorrhages, possible ulceration

Dx: duplex U/S - venous reflex

Tx:
wt loss
compressive dressings or stockings
leg elevation
topical steroids
vein ablation
35
Q

Pemphigus vulgaris

A

Flaccid bullae - easy to rupture (+ Nikolsky)
Oral lesions

Anti-desmosome Ab - epidermis

Tx:
High-dose systemic steroids
Azathioprine or mycophenolate mofetil (steroid-reducing adjuvant)
Abx for secondary infections

Prognosis: fatal if untreated, mortality of 5% with treatment

36
Q

Bullous pemphigoid

A

Tense bullae
Rare oral lesions

Anti-hemidesmosome Ab - dermal-epidermal junction (BM)

Tx:
Topical - clobetasol
Oral prednisone if topicals not possible
Chronic management: mycophenolate mofetil, azothioprine or methotrexate
Prognosis better than pemphigus
37
Q

Porphyria cutanea tarda

A

Deficiency in hepatic uroporphyrinogen decarboxylase

Risk: Hep C, alcohol abuse, excess iron

Chronic blistering of sun exposed skin - facial hypertrichosis, hyperpigmentation, pseudoscleroderma

Dx: elevated plasma porphyrins

Tx:
phlebotomy
Hydroxychloroquine
Avoid sun, alcohol, estrogens, iron supplements

38
Q

Acute porphyria presentation

A

Systemic symptoms
Abdominal pain, vomiting
Neuropathy
Mental disturbances

elevated urinary porphyrobiligen

39
Q

Actinic keratosis

A

Precancerous skin lesion
Risk: sun exposure

Erythematous papules with rough,, yellow brown scales

Bx: dysplasia of epithelium

Tx: topical 5FU, imiquimod and cryotherapy
-> squamous cell carcinoma

40
Q

Squamous cell carcinoma of skin

A

Skin cancer of squamous cells of epithelium

Risk: UVB exposure, arsenic exposure, fair complexion, radiation

Painless, well demarcated, scaly patch or plaque, erythematous, scaling

Tx: surgical excision (Mohs), radiation
5-10% mets

41
Q

Basal cell carcinoma

A

Most common skin cancer

Pearly papule with telangiectasias, +/- rolled edges with ulceration

Tx: surgical excision (Mohs), radiation, cryotherapy

less than 0.1% met

42
Q

Melanoma

A

Malignant melanocytes tumor - rapid spread

Risk: sun exposure, fair complexion, FHx, numerous nevi

Types:
Superficial spreading - MC, grows laterally before vertically
Acral lentiginous - least common, found on palms, soles, nail beds
Lengito maligna - slow growth, 10-50 yrs before vertical growth

Bx: atypical melanocytes with invasion of dermis
>0.76 mm risk mets

Tx: surgical excision
Insitu - 0.5 cm margin
less than 2 mm thick - 1 cm margin
>2 mm thick - 2 cm margin +/- LN dissection

Chemo/rad if mets

Mets -> lung, brain, GI tract

43
Q

Melasma

A

Dark skin discoloration, in pregnant women and those taking OCPs or HRT

Minimizing sunlight exposure and opaque sunscreen - titanium dioxide or zinc oxide

Triple combo cream - tretinoin, hydroquinone, mid-potency topical steroid - flucinolone

44
Q

Vitiligo

A

Sharply demarcated patches of complete depigmentation - due to loss of melanocytes

  • Borders are hyperpigmented
  • MC in acral areas, around body orifices

Skin texture is normal
Assoc with graves’ disease, autoimmune thyroiditis, pernicious anemia, T1DM, primary adrenal insufficiency, hypopituitarism, alopecia areata, autoimmune hepatitis

MC 20-30 yo

Tx:
Sunscreen to minimize tanning
Dyes and make up
Topical mid-pot corticosteroids first line (low potency kids)
Tacrolimus or pimecrolimus
Psoralens (topical or PO) + UV light
Surgical minigrafting
Hydroquinone for depigmentation - last resort
45
Q

Acanthosis nigricans

A

Brown to black velvety hyperpigmentation of the skin
Associated with T2DM, hyperinsulinemia and visceral malignancies

Tx underlying disorder

Tretinoin - topical
Calcipotriene - topical vit D analog

46
Q

treatment for infantile hemangiomas

A

Uncomplicated - gradually resolve within the first two years of life, observation best treatment

Complicated - oral propranolol, systemic glucocorticoids, vincristine, interferon alpha

47
Q

Alopecia areata

A

Asymptomatic, inflammatory, non-scarring areas a complete hair loss

Maybe precipitated by stress
Regrowth after first attack in 30% by 6 mo, 50% by 1 yr, 80% by 5 yr

R/o other cause - get syphilis screen, CBC, BMP, ESR, TSH, ANA
R/o trichotillomania

Tx:
intralesional steroid injections
topical corticosteroids
Topical minoxidil
Topical immunotherapy
Topical anthralin
Oral corticosteroids
48
Q

telogen effluvium

A

diffuse stress related hair loss

tx: reassurance, stress avoidance

49
Q

Androgenic alopecia

A

Hormonal and genetic causes

DHT causes follicular miniaturization -> replacement of terminal hairs by short, thin hairs

Tx: finasteride - 5a-reductase inhibitor
Topical minoxidil