Dermatology Flashcards
Acne vulgaris
Path:
Pt:
Tx:
Path: Blockage of follicular opening from hyperkeratinization; Increased sebum production: inflammation
Pt:
- Noninflammatory: closed comedones (white heads); open comedones (black heads)
- Inflammatory: papules, pustules, nodules cysts
- Nodulocystic: inc chance of permanent scarring
Tx: skin care
topical retinoids
topical antimicrobials (benzoyl peroxide, dapsone)
oral abx (tetracycline, doxycycline)
hormonal therapy (combo OCPs, spironolactone)
isotretinoin
Folliculitis
Path:
Tx:
Superficial hair follicle infection
S aureus MC
Tx: Topical mupirocin, clinda, erythromycin
Rosacea
Path:
Tx:
Path: Inflammatory d/o of flushing erythema, papules, pustules
Exacerbated by: UV light, heat, spicy foods, ETOH, stress, exercise, hormonal
Tx:
Topical metronidazole, sulfacetamide, ivermectin
BB suppress flushing
Isotretinoin for severe, refractory
Erythema multiforme Path: Pt: Dx: Tx:
Path: Type IV hypersensitivity reaction
Associations: Herpes
Major rxn associated w/ drugs: sulfa, beta-lactams, phenytoin, phenobarbital
Pt: Skin lesions evolve over 3 -5 days and persist about 2w
Dx: Target lesions Dull dusty-violet red Purpuric macules/vesicles or bullae in center surrounded by pale edematous rim and peripheral red halo Pt often febrile
Tx: self limiting, tx symptoms
D/C offending agents
steroid/lidocaine/diphenhydramine mouthwash
Stevens-Johnson syndrome Path: Pt: Dx: Tx:
Path:
Carbamazepine #1 med to cause this type of drug eruption
2nd MC cause-> mycoplasma pneumoniae infection
Pt: basal layer dusky, looks like erythema multiforme
Sloughing skin
Hemorrhagic erosions w/ a grayish white membrane on mucous membranes
Dx: <10% BSA
+nikolsky sign
Tx: Stop all meds
Burn unit
F/U oral, ophthalmology-> at risk for losing vision
Toxic epidermal necrolysis Path: Pt: Dx: Tx:
Path:
Carbamazepine #1 med to cause this type of drug eruption
2nd MC cause-> mycoplasma pneumoniae infection
Pt: full-thickness sheets of skin
Sloughing skin
Hemorrhagic erosions w/ a grayish white membrane on mucous membranes
Dx: >30% BSA
+nikolsky sign
Tx: Stop all meds
Burn unit
F/U oral, ophthalmology-> at risk for losing vision
Alopecia
Path:
Pt:
Tx:
Alopecia areata
Path: Immune-mediated disorder that causes recurrent, non-scarring hair loss
Pt: Autoimmune disease ; Complaining of hair loss
PE: patches of smooth, non-scarring hair loss w/ patches of smaller hairs termed exclamation hairs
Dx: Positive pull test: individual hairs are easily dislodged
Tx: Corticosteroids creams or injections Minoxidil Phototherapy Topical immunotherapy
Androgenic
Path: Genetic predisposition; ‘male pattern baldness’
Pt:
Men: Gradual thinning in temporal areas producing a reshaping of anterior part of hairline
Women: Diffuse thinning on crown; Frontal fringe remains
Tx: Minoxidil (rogaine); Finasteride
Onychomycosis
Path:
Dx:
Tx:
Path: Nail infection by various fungi:
-Tinea
-Candida
MC occurs on great toes
Dx:
KOH
Nail clipping (culture or PAS stain)
Tx: Itraconazole, terbinafine
Paronychia
Path:
Pt:
Tx:
Acute: S aureus, GAS rapid onset erythema, edema, pain of proximal and/or lateral nail folds following trauma/manipulation Tx: I&D Anti-staph topical/oral abx
Chronic Frequent hand washing, water work Absence of cuticle + erythema and edema of nail folds Yeast (candida) Tx: Topical antifungals (azoles) Topical steroids Proper hand/nail care
Erythema infectiosum Path: Pt: Dx: Tx:
(fifth disease; slapped cheek syndrome)
Path: Parvovirus 19
Pt:
Hx of URI 3-4 days prior to rash
Rash progression
1. Slapped cheek -> erythematous facial flushing
2. Diffuse macular erythema on trunk and proximal extremities -> lacy, reticulated appearance w/ central clearing of macular lesions
Fever AND rash
Dx: Clx
Tx:
Supportive
F/u:
Aplastic crisis in sickle cell
Hydrops fetalis if in utero
Hand-foot-mouth dz Path: Pt: Dx: Tx:
Path: Coxsackie A
Pt:
Mild fever, URI sx, decrease appetite
Oral enanthem: vesicular lesions w erythematous halos in oral cavity -> exanthem 1-2d afterwards: vesicular, macular or maculopapular lesions on distal extremities (often includes palms and soles)
Dx: Clx
Tx: Supportive: antipyretics, topical lidocaine
Measles Path: Pt: Dx: Tx:
Rubeola
Path: paramyxovirus; Measles virus
Portal of entry is through respiratory tract or conjunctivae following contact w/ large droplet or small-droplet aerosols in which the virus is suspended
Pt: High fever AND Rash Exanthem -> Koplik spots: pinpoint grey spots Cough Coryza Conjunctivitis Prominent exanthem Maculopapular rash first appear on face and spreads down truck, begins to coalesce and becomes confluent
Dx: Clx
Tx: Supportive
Complications: Diarrhea Pneumonia Acute disseminated encephalomyelitis Subacute sclerosing panencephalitis -> nearly always fatal
Mumps Path: Pt: Dx: Tx:
Path:
Mumps virus, rubulavirus
Incubation 16-18 days
Prior to MMR vaccine, MC affected school-aged children
Pt:
1-2 day prodrome: Low-grade fever, HA, malaise, vomiting
Followed by
tenderness, occasionally associated w/ earache
swelling of unilateral or bilateral salivary glands (usually parotid glands)
Parotid swelling can last up to 10 days
Dx:
Presence of parotitis, unvaccinated
Parotid swelling may obscure angle of mandible
Orifice of Stensen’s duct is erythematous and enlarged
Labs:
-Leukopenia w/ relative lymphocytosis
-Elevated serum amylase
Tx:
Supportive-> ibuprofen, acetaminophen
Complications:
Viral meningitis, encephalitis
Unilateral acquired sensorineural deafness
Orchitis (epididymoorchitis), oophoritis -> sterility
Pancreatitis
Arthritis
Thyroiditis
Rubella Path: Pt: Dx: Tx:
German measles
Path: Rubivirus
Pt:
Prodrome: generalized, tender Lymphadenopathy-> sub-occipital, post-auricular and anterior cervical
Low-grade Fever AND Rash
Rash begins on face and neck as small, irregular pink macules that coalesce, spreading centrifugally to involve the torso and extremities lasting generally 3 days
Oropharynx may reveal tiny rose colored lesions-> Forchheimer spots
sore throat, red eyes +/- eye pain, HA, malaise, anorexia
Dx: Clx
Tx: Supportive
Roseola Path: Pt: Dx: Tx:
Path: HHV-6
Pt:
6m to 3y/o
High fever THEN rash
Abrupt onset fever lasting 3-4 days
Fever resolved with the appearance of a faint pink or rose-colored, nonpruritic morbilliform rash on trunk
Rash: blanching maculopapular rash w/ distribution that begins at neck/trunk region and spread to face and extremities
Mild pharyngeal injection, enlarged suboccipital lymph nodes
Nagayama spots-> red papules on soft palate
ulcers at uvulopalatoglossal junction
Dx: Clx
Tx: Supportive
Varicella-Zoster infections
Path:
Pt:
Tx:
Path:
VZV reactivation along one dermatome of the dormant virus in spinal root and cranial nerve ganglia +/- disseminated in HIV
HHV 3
Pt:
Rash: Pain-> burning, throbbing, stabbing
Erythematous papules, grouped vesicles or bullae-> pustular
Within a single dermatome or several continuous dermatomes
-Herpes zoster ophthalmicus: shingles involving 1st division of trigeminal nerve (CN V)
-Hutchinson’s sign: lesions on nose usually heralding ocular involvement
-Dendritic lesions: seen on slit lamp exam if keratoconjunctivitis is present
-Herpes zoster Oticus (Ramsay-Hunt syndrome)
Facial nerve (CN VII)
otalgia, lesions on ear, auditory canal and tympanic membrane, facial palsy
-Auditory sx: tinnitus, vertigo, deafness, ataxia
-Post herpetic neuralgia: pain >3m, hyperesthesia or decreased sensation
Tx:
- Shingles: acyclovir, valacyclovir, famciclovir (given within 72hrs to prevent PHN)
- HZO: Po antivirals +/- trifluridine, acyclovir or vidarabine ophthalmic
- Ramsay Hunt syndrome: Oral acyclovir + corticosteroid
- PHN: Gabapentin or TCAs, topical lidocaine gel, capsaicin
Seborrheic keratosis
Path:
Pt:
Tx:
Path: Common, benign, hereditary
Pt: Light tan, almost opaque macules to dark-colored “warty” like plaques
Tx: Curettage or liquid nitrogen
No chance of malignancy
Actinic keratosis
Path:
Pt:
Tx:
Path: MC pre-cancerous skin lesion
Pt: Rough, scaly patch of skin
pink, red, brown
Tx: monitor vs remove-> can progress to SCC
Basal cell carcinoma
Path:
Pt:
Tx:
Path: Basal layer
Pt: Pearly lesion
Tx: Face-> mohs
Squamous cell carcinoma
Path:
Pt:
Tx:
Path: Malignant keratinocytes
Can mets
Locally invade
Pt: Either:
- well defined red papules or
- ulcer, non-healing, lower lip hyperpigmentation no paraneoplastic
Tx:
Face-> mohs
Limb mild-> excision
Limb aggressive-> amputate
Melanoma
Path:
Pt:
Tx:
Path: Melanocytes
Can mets
Locally invade
Pt: Jet black lesions w/o hair OR Asymmetric Borders Color Diameter >5mm Evolving
Tx: Lesions size/ margin size
<0.5mm= excision/ 0.5cm
1-2mm= excision/ 1cm
2-4mm= excision/ 2cm
* + sentinel lymph node dissection if tracer is +
>4mm-> metastatic; chemo + radiation; palliative debulking
Melanoma subtypes
Superficial spreading (50-60%): Long horizontal growth phase before vertical growth phase-> better prognosis
Lentigo maligna (4-10%): Lentiginous proliferation indicates the tumor remains at the junction
Best prognosis
AKA “Hutchinson freckle”
Acral lentiginous (2-3%): Typically found in subungual (under nail), sole or palm location
Common in ethnic groups of color
Not related to UV exposure
Nodular (10-30%): Worst prognosis
Rapid vertical growth, increased metastatic potential
Cellulitis
Path:
Pt:
Tx:
Path: SubQ
Staph-> burrow in, abscess
strep A-> spread out, no abscess
Pt: Red, hot tender
Well-demarcated portal of entry
Dx-> clx
Tx: Demarcate w/ pen after initiation of abx
Nontoxic:
Strep-> 1st gen ceph (po)
Staph-> tmp-smx (po), clinda
Toxic:
Strep-> pip/tazo, amp/clavulanate
Staph-> vanc, linezolid (IV), clinda then transition to po
F/U: diabetic foot ulcer, osteomyelitis
Erysipelas
Path:
Pt:
Tx:
Path: Strep
Pt:Adult
Dark red, well-defined, indurated
“climbing”
dx-> clx
Tx: Amoxicillin
Impetigo Path: Pt: Tx: Complications:
Path: Highly communicable (auto-inoculation) cutaneous infection w/ S aureus or GAS
Classifications: Nonbullous- MC Impetigo contagiosa: vesicles, pustules -> characteristic “honey-colored” crusts Associated regional lymphadenopathy Path: S aureus (MC), GABHS
Bullous - rare usually seen in newborns/young children
Vesicles form large bullae (rapidly)-> rupture -> thin “varnish-like crusts”
Fever, diarrhea
S aureus (MC)
Ecthyma- not common
Ulcerative pyoderma caused by GABHS
Heals with scarring
Pt: <6yrs; non-painful, pruritic, honey-colored, weeping lesions on face
Tx: Topical mupirocin TID x10d Extensive disease or systemic sx-> oral abx Cephalexin Dicloxacillin, clinda erythromycin, azithro, clarithromycin
Complication:
Post-streptococcal glomerulonephritis
Tinea capitis
Pt:
Tx:
Pt: “ringworm”
Annular scaling lesions & brown hair shafts
Inflamed plaques with multiple pustules (kerion) w/ scarring and alopecia
Tx:
PO griseofulvin 1st line
PO terbinafine, itraconazole, fluconazole
Tinea Barbae
Pt:
Pt: Papules, pustules & hair follicles
Tinea pedis
Pt:
Tx:
Pt: “athlete’s foot”
Pruritic, scaly eruption rash between toes
Tx:
Topical antifungal (PO griseofulvin is ineffective)
Clean shoes w/ antifungal spray, keep cool and dry
Tinea Cruris
Pt:
Tx:
Pt: “jock itch”
Diffusely red rash on groin or scrotum
Tx: Topical antifungals (PO griseofulvin is ineffective)
Tinea Corporis
Pt:
Tx:
Pt: Erythematous plaques (circular rash w/ clear center & defined borders), scaling, cracking and vesicles
The presence of scales in tinea corporis distinguished it from erythema migrans
Tx: Topical antifungals (PO griseofulvin is ineffective)
Tinea versicolor
Pt:
Dx:
Tx:
Pt: Scaly, salmon-colored, well demarcated papules and plaques with variable pigmentation
Typically located on trunk, neck, upper extremities
Dx:
KOH+ for Malassezia furfur (spaghetti and meatballs)
Wood’s lamp
Tx:
Selenium sulfide shampoo
Ketoconazole shampoo
Lice
Path:
Pt:
Tx:
(pediculosis capitis “head lice”)
Path: Infestation w/ pediculus capitis, obligate human parasite that cannot survive off host for more than 10 days
Pt: Child complaining of itching on their head w/ nits (eggs) or actual lice
Tx: Permethrin (2nd treatment 9 days after 1st treatment to ensure eradication)
Scabies Path: Pt: Dx: Tx:
Path:
Sarcoptes scabiei-> mites transmitted through
-Prolonged, close skin contact
-Fomites (clothing, bedding)
Cannot survive off human body >4 days
Female mites burrow into skin to lay eggs, feed and defecate
Pt:
Intensely pruritic lesions (papules, vesicles) & linear burrows
Intertriginous zones: Web spaces between fingers/toes, Scalp, Usually spares neck and face
Increased intensity at night
Dx:
Clx
Skin scraping of burrows w/ mineral oil to ID mites/eggs under microscopy
Tx:
- Permethrin : Apply topically from neck to soles of feet for 8-14 hrs then shower; Repeat in 1 week
- Lindane : Cheaper; DO NOT use after a shower-> seizures; Teratogenic-> do not use in breastfeeding women, children <2y
Condyloma acuminatum Path: Pt: Dx: Tx:
Path: HPV genital wart
Pt:
Wart-like papules resembling a rooster’s comb
tiny, painless papules evolve into soft, fishy cauliflower-like lesions rating from skin-colored to pink or red; occurring in clusters in genital regions and oropharynx. Lesions persist for months and may spontaneously resolved, remain unchanged or grow if not treated
Dx: Inspection; Histology; Typing HPV
Tx: Tx sexual partner at the same time Curettage Podophyllin Electrocoagulation Laser Chemical Salicylic acid Cryotherapy
Molluscum contagiosum
Path:
Pt:
Tx:
Path: pox virus
Pt: Umbilicated papules
Tx: no tx vs Curettage/ Electrocoagulation
Verrucae
Path:
Pt:
Tx:
Path: Cutaneous HPV
Pt:
-Common and plantar warts: firm, hyperkeratotic papules between 1-10mm w/ red-brown punctuation (thrombosed capillaries are pathognomonic); common on hands
-Flat warts (verruca plana): numerous, small discrete, flesh-color papules measuring 1-5mm in diameter and 1-2mm in height, typically seen on face, hands, shins
Tx: topical OTC salicylic acid and plasters Cryotherapy Electrocautery CO2 Laser Intralesional bleomycin
Kaposi sarcoma
Path:
Pt:
Tx:
Path
HHV-8 + immune suppression (usually HIV)
AIDS defining illness
Pt: Multiple, spongy, compressible, vascular nodules in the skin, mucosa and other organ systems
Indolent (skin involvement) to fulminant (internal organ and lymphatic system)
Tx:
Identify and rectify (if possible) source of immunosuppression
Surgical removal, laser therapy
Radiotherapy or chemo
