Common Infections Of The Skin Flashcards
What are the most common types of bacteria for skin infections
Gram (+)
- especially staph aureus
Impetigo
Caused by staph and GAS
**Most common bacterial skin infection in pediatrics
Shows honey-colored crusted plaques/papules/vesicles/Bullae
Also called “impetiginized” skin
- “ecthyma” is deeper more punched out impetigo (looks kinda like gun shot wounds)
- specific treatment for ecthyma = cephalexin
Complications = rare and usually benign (only 5% leads to any of the below)
- post streptococcal Glomerulonephritis
- staph scaled skin syndrome
Treatment = mupirocin or retapamulin ointment
Folliculitis
Superficial or deep infections around hair follicles
- **staph aureus is most common pathogen
- **“hot tub” folliculitis is from pseudomonas however
Risks = occlusion, sweating/increased humidity, increased steroid use, poor shaving/hygiene
Forms follicular based erythematous papules/pustules
Treatment = antibacterial washes, mupirocin
- oral doxycycline as last line or complications
Pseudofolliculitis barbae
Folliculitis caused by poor shaving practices and results in irritation
- looks kinda like folliculitis but is caused by curving of the hair follicle which causes the tip of the hair follicle to embed back into the the skin and cause inflammatory response to the keratin in the hair.
Treatment = change shaving practices and a topical clindamycin aftershave
Gram (-) folliculitis
Caused by patients who are using long term steroids or oral antibiotics
Treatment = isotretinoin (accutane)
Furuncle/carbuncle
Furuncle = folliculitis that looks like a boil
- surrounding tissue is also acted on
Carbuncle = groups of furuncle and presents with systemic system
Treatment = oral antibiotics and topical antibiotics as needed
Abscesses
Can be anywhere on the skin and is localized collection of pus that causes inflamed skin
Treatment = incision and drain as needed, culture, and then antibiotics and pack the abscess
Cellulitis
Most commonly caused by GAS and Staph aureus
Immunocompentent = must have had a break in the skin Immunocompromised = could also be blood borne
Produces erythema, warmth, tenderness and irritation
- bilateral cellulitis = venous stasis dermatitis MUST be #1 on your differential*
- normal cellulitis is more commonly unilateral
Erysipelas
St. Anthonys fire
Superficial variant of cellulitis that usually is on the face
- is caused by GAS
- more common in females vs males and bimodal distribution with. Young and elderly
Incubation of 2-5 days and then abrupt onset of fever, chills and malaise.
- also reports burning sensations and lymphadenopathy
Treatment = doxycycline usually
Perianal strep
Caused by GAS
- more common in males <4 yrs
Almost always preceded strep throat or colonization of the tonsils (but not necessarily)
Shows pain, pruritis, blood/fecal incontinence in stool
- shows erythematous nummular patch around the anus
- **no systemic symptoms
Need to rule out candida, pinworms and IBD
Tx= topical antibiotics (mupirocin) and oral cephalosporin
Pitted keratolysis
Caused by corynebacterium, actinomycosis and kytococcus sedentarius organisms
- ***all of these secrete proteases specific to the stratum corneum and causes sponge like holes in the stratum corneum
- almost always on the feet and smells horrific also
Risk factors = humidity, hyperhydrosis (over sweating) and occlusion
Treatment = topical erythromycin/Clindamycin
- also give aluminum chloride or Botox if the patient has super sweaty feet
Verrucae vulgaris (warts)
Caused by HPV (most common are 6/7 subtypes)
Hyperkeratosis papules/plaques that grow overtime
- also can cause thrombotic capillaries with in the wart (this confirms its a wart and looks like black spots)
- also shows interruption of dermatoglyphs (lines in the skin get disrupted)
Treatment = very difficult!
- cryotherapy is #1
- Topical such as cantharidin/salicylate Acid and 5-FU combo therapy/cimetidine
- immunotherapy
- laser therapy
- injection of candida species
- HPV vaccine (prophylaxis only, doesnt treat active warts)
Molluscum contagiosum
Most common Pox virus infection
- very common in children
- if patient is immunocompromised = giant lesions
Shows pearly red papules with central dell on them
- Is sexually trasmittable but also contact as well
Patients with eczema are also at very high risk since their stratum corneum is naturally deficient
Treatment = benign and self-limiting, however can also give topical irritants (cantharidin)
Hand foot mouth disease
Coxsackie A16 or enterovirus 71 causes it
- coxsackie A6 = more severe bullous form
Shows gray/white vesicular lesions on the palmoplantar skin
- also shows systemic symptoms such as fever, malaise, anorexia, dehydration
Treatment = supportive only
Erythema infectiousum
“Fifth disease/ slapped cheek disease”
Parvovirus B19 causes this and is spread via respiratory droplets
- almost exclusive to 4-10 yrs old
Prodromal symptoms of fever, headaches and malaise
- once rash starts = not infectious any more
Treatment = supportive and goes away
