Dermatology Flashcards
MCC Cellulitis in adults
Group A Strep
Other Causes: Staph A,
MCC Cellulitis in Neonates
Group B Strep
Etiology of cellulitis & Symptoms
Breaks in skin, bites, etc.
Erythema, warmth, induration, pain, LAD, fever, edema
Although cellulitis is a clinical diagnosis mainly, what can be seen on US?
Cobblestoning appearance
If an abscess is present, what is the MCC?
Staph A
Explain erysipelas (form of cellulitis)
Superficial skin infection involving local lymphatics
Sharp, demarcated border on LE or face, indurated, pruritic, painful
MCC of erysipelas
Strep Pyogenes
Treatment for erysipelas
Oral: PCN, Amoxicillin, Cephalexin
IV: Cefazolin, Ceftriaxone
The MC form of impetigo is _____ and the MCC of impetigo is _____
Non-bullous
Staph A
Explain the rash of impetigo
Honey-colored crusts
Face and extremities MC
Erythematous macule –> pustule
Treatment for Impetigo (non-medical and medical)
-Remove crusts with warm cloth
-Mupirocin topical
-Avoid scratching
-oral ABX if severe (Doxy, Clinda, Bactrim if MRSA)
Acne vulgaris is overproduction of _______ and has four parts to the pathophysiology. Name them.
Sebaceous glands
1) follicular hyperkeratinization, 2) increased sebum production, 3) propioniobacterium overgrowth, 4) inflammatory response
Open comedones (_____) and closed comedones (_____) are symptoms of which type of acne?
Open: blackheads
Closed: whiteheads
Mild
Treatment for acne vulgaris
Mild: Topical (Azelaic acid, salicylic acid, benzoyl peroxide, Clindamycin ointment
Moderate: Topical + Oral (Mino, Doxy, Spironolactone)
Severe: Oral Isotretinoin
What are some adverse effects to isotretinoin?
Dry skin/lips, teratogenic, increased cholesterol and triglycerides
What are some triggers for rosacea?
Alcohol, cold/heat, spicy foods, hot drinks, sun exposure
Symptoms of rosacea
-Intermittent facial flushing
-No comedones
-telangiectasias
-Rhinophyma
First-line medical treatment for rosacea
Topical metronidazole
Others: Tetracyclines, laser therapy
However, for facial erythema, you can use
Topical Brimonidne
Bullous pemphigoid is a Type ______ hypersensitivity reaction that occurs in what population?
Type IV
Elderly
Explain the rash of bullous pemphigoid
-Negative Nikolsky
-Low mortality
-Tense bullae that do not rupture easily
-Rarely oral lesions
-Pruritic lesions with urticarial plaques
The gold standard diagnostic for bullous pemphigoid is
Skin biopsy with direct immunofluorescence
Treatment for bullous pemphigoid
Topical corticosteroids, but systemic if severe
Pemphigus vulgaris, on the other hand, occurs in what population? What are the symptoms of this condition?
Younger people, life threatening
-Positive Nikolsky
-Painful erosion
-Oral lesions (MC)
-Flaccid skin bullae that rupture easily
What are two medications that likely can cause pemphigus vulgaris?
Captopril & Penacillamine
Treatment for pemphigus vulgaris?
Systemic high dose corticosteroids and local wound care
Erythema Multiforme, a Type IV hypersensitivity reaction, has etiologies in
HSV (MC)
Mycoplasma (in kids)
Meds: Sulfa, Allopurinol, Phenytoin
Symptoms of erythema multiforme
Target lesions: dusky with pale ring and halo in periphery
Negative Nikolsky
Palms and soles affected!!!!
Explain the difference between Erythema Multiforme minor and major
Minor: No mucous membrane involvement
Major: mucous membrane involvement (oral, genital, ocular)
Treatment for erythema multiforme
-D/C offending drug
-If HSV related: Acyclovir
-Diphenhydramine mouthwash (oral lesions)
Steven-Johnson Syndrome and TEN are associated with detachment of the epidermis and necrosis. What occurs in this condition?
Sloughing (dermal-epidermal cleavage)
Explain the difference in SJS and TEN
SJS: < 10%
TEN: > 30% sloughing
Risk factors for SJS and TEN
MC: Meds (Sulfa (PCN), Lamotrigine, anticonvulsants, NSAIDs, and Allopurinol)
Infections: HSV, HIV
Symptoms of SJS and TEN
-Rarely soles and palms
-Widespread flaccid bullae (trunk/face)
-Target lesions with mucous membrane involvement
-Positive Nikolsky sign
-Ocular involvement (uveitis, corneal ulcer)
Treatment for SJS/TEN
D/c causative agent
Burn unit/ICU admission
IVIG
Eczema (atopic dermatitis) is part of the atopic triad. Name the triad.
Eczema + asthma + allergic rhinitis
Most eczema manifests by what age? What is the gene mutation?
Infancy or age 5
Filaggrin gene mutation
Triggers for eczema
Heat, allergens, perspiration, contact
Symptoms of eczema
-Excoriation
-Pruritis (hallmark)
-MC in flexor creases (behind knee, elbow, etc.)
-Nummular: coin shaped lesions on dorsum of hands, feet, knees, and elbows
Treatment for acute eczema
-Topical corticosteroids (first line)
-Antihistamines for itching
-Wet dressings
-Calcineurin inhibitors: Tacrolimus, Pimecrolis
Treatment for chronic eczema
Systemic phototherapy
Methotrexate
Oral antihistamines
Trigger avoidance
Contact dermatitis has two types. Name them and which is more common?
Irritant (MC) and allergen
What are some causes of allergen contact dermatitis?
Nickel (MC), poison ivy, poison oak, poison sumac
Contact dermatitis is a Type IV hypersensitivity reaction. What is the difference in symptoms showing up in allergen related vs irritant?
Allergic: delayed by days
Irritant: immediate
Treatment for contact dermatitis
Topical corticosteroids
-Burrow’s solution, cool compresses, etc.
What is toxicodendron dermatitis? What is the cause?
Contact dermatitis due to plants (oak, ivy, sumac)
The urushiol in plants causes this
What is diaper rash?
Type of irritant contact dermatitis
Dyshidrosis, also known as pomphlyx, is a recurrent rash affecting which area of the body? Describe it.
The palms and soles
Tapioca-like, pruritic vesicles on soles, palms, and fingers
Treatment for dyshidrosis
Topical corticosteroid ointments
Cold compresses, Burrow solution
Dry hands, use cotton gloves, etc.
What is Lichen Simplex Chronicus?
Skin thickening in patients with atopic dermatitis due to rubbing and scratching
Symptoms of lichen simplex chronicus
scaly, well-demarcated plaques, exaggerated skin lines
Treatment for lichen simplex chronicus
Avoid scratching
Topical corticosteroids
Occlussive dressings
What is the pathophysiology of psoriasis?
Keratin hyperplasia and proliferating cells in the stratum basalt and stratum spinosum due to T cell activation and cytokine release
-Accelerated epidermis turnover
Symptoms of psoriasis
-Plaques: raised well-demarcated, pink plaque with thick silvery white scales MC on EXTENSOR surfaces (elbows, knees, scalp, and neck)
Nail involvement: pitting, oil spot (yellow discoloration under the nail)
What is the Auspitz sign associated with psoriasis?
Bleed with removal of plaque
What is Koebner’s Phenomenon associated with psoriasis?
new lesion at the site of trauma
Guttate psoriasis is associated with ______ and has symptoms such as _______
Occurs after strep pharyngitis
Tear drop plaques that spare palms and soles
Treatment for mild-moderate psoriasis?
Topical corticosteroids (Betamethasone, Clobetasol)
Vitamin D analogs (Calcipotriene)
Calcineurin inhibitors (Tacrolimus, Pimecrolus)
For moderate to severe psoriasis, use
Phototherapy, UVB, PUVA
If systemic psoriasis, what is the treatment?
Systemic treatment
-Retinoids (Acitretin)
-TNF Inhibitors (Etancercept, -mabs)
-Methotrexate (last resort)
Psoriatic arthritis, a systemic disease, is associated with what?
HLA-B27 positivity
Where does psoriatic arthritis usually affect?
Distal IP arthritis
Treatment for psoriatic arthritis
Methotexate, Cyclosporin
