Derm Conditions and ABX

Question 1

Comedomes tx

Answer 1

Topical Retinoids

Question 2

Papules, pustules, nodules, and cysts indicate what bacteria?

Answer 2

Gram (+) anaerobes Cutibacterium acnes (P acnes)

Question 3

Mild acne (papules and pustules) tx

Answer 3

Topical Retinoids + Benzoyl peroxide

Question 4

Moderate acne (papules and pustules) Tx

Answer 4

Topical Abx— Erythromycin or clindamycin

Question 5

Severe acne (papules and pustules) Tx

Answer 5

PO Abx— Tetracycline class Doxycycline

Question 6

Acne Nodules or cysts treatment

Answer 6

Mild/Moderate:
—Topical retinoid + Benzoyl peroxide + topical abx (clindamycin/erythromycin)

Severe:
—PO abx Doxycycline

Question 7

Treatment for acne that is unresponsive to therapy or is scarring

Answer 7

PO Isotretinoin

Question 8

Tetracyclines MOA, SOA, and ADRs

Answer 8

MOA: Inhibits bacterial protein synthesis via 30S ribosomal subunit

SOA: broad Gram (+ & -) including MRSA and atypicals (chlamydia, mycoplasma, vibrio cholera)

ADRs: Photosensitivity and esophagitis. Renal except for doxycycline
Contraindicated in kids <8 and in pregnancy/breast feeding

Question 9

What is rosacea and how does it present?

Answer 9

A chronic Acneiform cutaneous inflammatory rxn.
Face is most commonly involved.
Most common in women ages 30-50yo.

Etiology is unclear:
—Persistent vasomotor instability, capillary vasodilation, and abnormal pilosebaceous activity

Presentation:
—Facial flushing of the nose/cheeks/lip margins 
—+/- telangiectasias
—papules and pustules. 
—Rhinophyma=red enlarged nose

absence of comedomes (blackheads) distinguishes it from acne

Triggers are sun, alcohol, spicy foods, stress, exercise, cold/hot.

Question 10

Isotretinoin MOA, and ADRs

Answer 10

MOA: affects all 4 of the pathophysiologic mechanisms of acne and is the most effective med for acne vulgaris.

ADRs:
—Dry skin and lips (most common)
—Dry eyes
—Highly teratogenic MUST obtain at least 2 neg pregnancy tests prior to initiation and monthly while on treatment
—Increased triglycerides and cholesterol
—worsening of DM, arthralgias, leukopenia, immature long bone closure

Question 11

Metronindazole MOA, clinical use, and ADRs

Answer 11

MOA: creates free radicals in bacterial cells that break DNA

Clinical use: Protozoa (amoeba, giardia, trichomonas) and Anaerobes (C diff, Gardnerella, bacterial vaginosis, H pylori)

ADRs: HA, metallic taste, disulfiram like rxn if taken w alcohol use

Question 12

Clinical Pearl: Clindamycin treats anaerobes _________ and metronindazole treats anaerobes _________

Answer 12

Clindamycin treats anaerobes above the diaphragm and metronindazole treats anaerobes below the diaphragm

Question 13

What is erysipelas

Answer 13

Variant of cellulitis involving upper dermis: Inflammation of the superficial dermis +/- lymphatic involvement , fever and chills.
Caused by STREP PYOGENES.

A RAISED rash with SHARPLY DEMARCATED BORDERS. Tenderness and warmth

Most commonly involves lower extremities, face, or skin with impaired lymphatic drainage. Can involve ear (Milan sign)

**Unlike cellulitis> this is often associated with systemic manifestations— fever/chills/leukocytosis

Question 14

Erysipelas Treatment

Answer 14

Outpatient:
— PO Amoxicillin, Penicillin, or Cephalexin. If PCN allergy; Clindamycin, SMX, or linezolid can be used.

If severe w systemic sx:
—IV cefazolin, Ceftriaxone

If MRSA suspected:
—Vancomycin

**if severe/systemic sx get blood culture or US w gram stain of expressed fluid if underlying abscess

Question 15

Penicillin clinical use and ADRs

Answer 15

Penicillin V= PO
Penicillin G= IV & IM

Clinical use:
—Spirochetes (syphilis)
—Gram + aerobes (Strep Pyogenes)

ADRs: Rash, GI

Question 16

Aminopenicillins (extended spectrum) Use and ADRs

Answer 16

Amoxicillin/Augmentin= PO or IV
Ampicillin= IV

HHEELPSSS broadens PCN SOA:
H pylori/H flu, E. Coli/Enterococci, Listeria, Proteus, Strep Pneumo/Salmonella/Shigella

Use: PUD, bacteria, URIs

ADRs: Rash, diarrhea, C diff super infection

Question 17

What is Cellulitis and how does it present?

Answer 17

An acute spreading infection of the deeper dermis and subcutaneous tissues. Bacterial entry usually after a break in the skin d/t underlying skin problems/trauma/surgical wounds.

Most commonly GROUP A STREP. Staph Aureus is an important but less common cause

Presentation:
—localized macular erythema with FLAT margins that are NOT sharply demarcated
—Swelling, warmth, and tenderness
—Systemic sx are not common but may develop lymphangitis streaking

Question 18

Cellulitis Treatment:

Answer 18

Mild/Moderate/Outpt:
—Cephalexin or Dicolxacillin. Clindamycin or erythromycin if PCN allx
—if MRSA concern: Clindamycin, Doxycycline. TMP SMX is good for staph but doesnt cover strep.

Severe/inpt empiric:
—IV Abx: Cefazolin, Ampicillin-sulbactam, Ceftriaxone, & Clindamycin
—IV MRSA: Vancomycin or Linezolid

Cat or dog bite: Cover Pasturella gram (-)
—Augmentin
— Clindamycin + either ciprofloxacin or TMP SMX if PCN allx

Question 19

What is Folliculitis

Answer 19

Superficial hair follicle infection or inflammation. RF: more common in men, with prolonged abx use or topical corticosteroid use.

STAPH AUREUS most common
PSEUDOMONAS AERUGINOSA for hot tube related folliculitis.

Presents:
— singular or cluster of perifollicular papules and or pustules with surrounding erythema on hair bearing skin.
—often pruritic

Question 20

Folliculitis Tx

Answer 20

Mild:
— Topical mupirocin, Clindamycin, Erythromycin, or BPO

Severe or Refractory:
— PO Abx: Cephalexin or Dicloxacillin

Gram (-):
—Daily Acetic acid or topical BPO (usually resolves without treatment)

Question 21

How is Rosacea treated?

Answer 21

—Avoid triggers and wear sunscreen (toners, astringents, menthols, and camphor are irritants)

Mild/Moderate:
— TOPICAL METRONINDAZOLE is first line for papulopustules.
—Azelaic acid, ivermectin cream
— Sulfacetamide, anti acne topical abx

Moderate/Severe:
— Oral abx: Tetracyclines
—Laser therapy

Refractory:
—Oral Isotretinoin may be used

Facial erythema:
—Topical Brimonidine
—Laser or intense pulsed light therapy