ID E1- Derm & Infestations

Staph or Strep:

Catalase positive

Staph

Staph or Strep:

Catalase negative

Strep

What pathogen is the MCC of folliculitis?

Staph

What pathogen causes Hot tub folliculitis?

Pseudomonas A.

What abx are used to treat folliculitis?

Topical - Mupirocin, Clindamycin

What is the treatment for folliculitis caused by pseudomonas?

Good hygeine, Cipro if severe

What is an abscess?

circumscribed collection of pus appearing as an acute or chronic localized infection with tissue destruction

What is a furuncle?

acute, deep-seated, red, hot, tender nodule or abscess that evolves from a staphylococcal folliculitis

What is a carbuncle?

deeper infection composed of interconnecting abscesses usually arising in several contiguous hair follicles

What are boils?

furuncles

What is the treatment for furuncles?

Warm compress, I&D, Abx if >2cm

What is the treatment for carbuncles?

Swab for culture, I&D PLUS ABX

When is IV therapy/admission necessary for treatment of carbuncles?

systemic signs of toxicity, surrounding cellulitis, Immunocompromised, Unable to tolerate or failure of oral abx, Abscess is close to catheter

What are the preferred oral agents for treatment of skin/soft tissue infections due to MRSA?

Bactrim, Clindamycin, Doxycycline, Minocycline

What age range is impetigo most common in?

2-5 y/o

What pathogens cause nonbullous impetigo?

Staph aureus, GABHS

What pathogens cause bullous impetigo?

primarily staph aureus

How does Impetigo present?

pustules that progress to erosions covered by honey-colored crusts; painless

What is the treatment for mild/localized non-bullous impetigo?

Topical Mupirocin, Warm compress, Cephalexin or Docloxacillin

What is the treatment for bullous impetigo/extensive disease?

Same as non-bullous

PLUS Doxy/Bactrim/Clindamycin

What is Ecythyma?

ulcerative form of impetigo

How does Ecthyma present?

"Punched-out" ulcers covered with yellow crust surrounded by raised violaceous margins

Bullous impetigo can progress to what disease?

SSSS

What pathogens most commonly cause cellulitis?

Staph (MRSA/MSSA), Group A strep

What pathogen causes cellulitis due to meat/fish exposure?

Erysipelothrix rhusiopathiae

What pathogen causes cellulitis after saltwater exposure?

Vibrio vulnificus

In patients with cellulitis, you should NEVER take a culture from what area?

Intact skin; only from abscess or bullae

What IV therapy is used for cellulitis?

Vancomycin

What is another name for SSSS?

Ritter's disease

What age group is affected by SSSS?

Infants & children <6 y/o

Which disease would have a positive Nikolsky's sign?

SSSS

What is the only way to differentiate SSSS from SJS/TEN?

Skin biopsy

What is the treatment of SSSS?

ICU admission, IVF, IV abx directed towards staph aureus

What pathogen is the MCC of toxic shock syndrome?

Staph aureus (MSSA)

What is Toxic shock syndrome associated with?

tampon use, nasal packing, or wound packing

What are some symptoms of toxic shock syndrome?

Fatigue, Abdominal pain, Rash, HA, Sore throat, Hypotension, Orthostatic dizziness/syncope

How does Toxic shock syndrome present?

diffuse, red, macular rash with bullae formation resembling a sunburn, INVOLVING PALMS/SOLES, followed by desquamation

How many organ systems must be involved in order to dx TSS?

≥3

What is the MC complication of toxic shock syndrome?

Prolonged hypovolemic shock

What is the treatment for toxic shock syndrome?

IV abx: clindamycin + vancomycin + beta lactam

(need MRSA/MSSA coverage)

What pathogen is the MCC of erysipelas?

GABHS (S. pyogenes)

How does Erysipelas present?

butterfly pattern involving both cheeks/spread across the nose

How is strep throat transmitted?

Direct person to person contact

What is the first line treatment for strep throat?

PCN V po

What is Scarlet fever?

complication of strep pharyngitis that presents with strawberry tongue & rash

Where does the "sandpaper" rash associated with scarlet fever typically begin? Does it affect the palms & soles?

Axillae, groin, neck; spares palms and soles

How does Scarlet fever present?

fine, papular or punctate lesions that has a coarse, sandpaper texture + pastia lines

5 major manifestations of rheumatic fever

Carditis

CNS involvement (ie chorea)

Erythema marginatum

Polyarthritis (large joints)

Subcutaneous nodules

4 minor manifestations of rheumatic fever

Arthralgia

Fever > 100.4F

Elevated ESR/CRP

Prolonged PR interval (>0.2 secs)

Jones criteria for rheumatic fever

Initial episode with evidence of preceding GAS infection, PLUS:

Two major manifestations, OR

One major + two minor manifestations

What is the treatment for eradication of GAS for rheumatic fever?

IM PCN G

What is another name for Erythema infectiosum?

"Fifth disease"

What virus causes erythema infectiosum?

Parvovirus B19

How does Erythema infectiosum present?

"Slapped cheek" appearance with lace-like rash on body and circumoral pallor

Whats another name for Roseola?

"Sixth disease"

What is Pediculosis capitis?

Head lice

What is Pediculosis corporis?

Body lice

What is Pediculosis pubis?

Pubic lice/"crabs"

What is the drug of choice for treatment of pediculosis?

Permethrin

What causes the itching associated with Scabies?

delayed type IV hypersensitivity reaction to mites

How does Scabies present?

nocturnal pruritus, elevated S-shaped tracks on the skin at clothing lines

What is the treatment for scabies?

Permethrin cream; Remove by shower/bath after 8-14 hours, Repeat in 1-2 weeks

What are the two bedbug species that MC affect humans?

C. lectularius, C. hemipterus

When does peak activity of bedbugs occur?

Just before dawn

What type of infestation produces a peculiar pungent odor, and commonly affects environments that are in disarray?

Bedbugs

What is the treatment for bedbug bites?

Usually self-limiting; may use steroid cream or oral antihistamine