Podcast
Questions and Answers
A young child presents with honey-colored crusted lesions around the nose and mouth. Which bacterial species is most likely responsible for this condition?
A young child presents with honey-colored crusted lesions around the nose and mouth. Which bacterial species is most likely responsible for this condition?
- Streptococcus pyogenes
- Pseudomonas aeruginosa
- Staphylococcus aureus (correct)
- Vibrio vulnificus
A patient is diagnosed with bullous impetigo. Which pathophysiologic mechanism primarily contributes to the formation of the characteristic bullae?
A patient is diagnosed with bullous impetigo. Which pathophysiologic mechanism primarily contributes to the formation of the characteristic bullae?
- Inflammation of the subcutaneous fat
- Vascular damage leading to localized edema
- Release of exfoliative toxin A causing loss of cell adhesion (correct)
- Direct invasion of the dermis by bacteria
A patient is diagnosed with non-bullous impetigo with more than five lesions. What is the recommendation for treatment?
A patient is diagnosed with non-bullous impetigo with more than five lesions. What is the recommendation for treatment?
- Systemic antibiotics (correct)
- Observation only, as it is self-limiting
- Topical antibiotic ointment alone
- Topical antifungal cream
A football player develops a painful, erythematous, and edematous area on his lower leg after sustaining a minor abrasion during practice. He has a history of MRSA colonization. What is the MOST appropriate initial antibiotic treatment choice?
A football player develops a painful, erythematous, and edematous area on his lower leg after sustaining a minor abrasion during practice. He has a history of MRSA colonization. What is the MOST appropriate initial antibiotic treatment choice?
What is a key differentiating factor in the pathogenesis of cellulitis compared to erysipelas?
What is a key differentiating factor in the pathogenesis of cellulitis compared to erysipelas?
An elderly patient presents with a bright red, raised, and well-demarcated area of skin on their cheek, accompanied by fever and chills. What is the MOST likely diagnosis?
An elderly patient presents with a bright red, raised, and well-demarcated area of skin on their cheek, accompanied by fever and chills. What is the MOST likely diagnosis?
A patient with Type 1 diabetes develops cellulitis around a surgical wound and is being discharged from the hospital. What underlying condition increases their susceptibility to developing cellulitis?
A patient with Type 1 diabetes develops cellulitis around a surgical wound and is being discharged from the hospital. What underlying condition increases their susceptibility to developing cellulitis?
What clinical feature is MOST characteristic of erysipelas compared to cellulitis?
What clinical feature is MOST characteristic of erysipelas compared to cellulitis?
A public health nurse investigates an outbreak of folliculitis among members of a swim club using the same hot tub. Which organism is MOST likely responsible for this outbreak?
A public health nurse investigates an outbreak of folliculitis among members of a swim club using the same hot tub. Which organism is MOST likely responsible for this outbreak?
A young adult presents with numerous small, inflamed pustules around hair follicles on their chest and back, which are mildly pruritic. The patient reports using an antibacterial soap twice daily. What is the most appropriate first-line treatment?
A young adult presents with numerous small, inflamed pustules around hair follicles on their chest and back, which are mildly pruritic. The patient reports using an antibacterial soap twice daily. What is the most appropriate first-line treatment?
A patient presents with classic symptoms of Erysipelas, and has a known allergy to penicillin based drugs. Which antibiotic would be MOST appropriate to prescribe?
A patient presents with classic symptoms of Erysipelas, and has a known allergy to penicillin based drugs. Which antibiotic would be MOST appropriate to prescribe?
A dermatology clinic is conducting a community outreach program focused on the prevention of common bacterial skin infections. Which of the following recommendations should be emphasized to reduce transmission?
A dermatology clinic is conducting a community outreach program focused on the prevention of common bacterial skin infections. Which of the following recommendations should be emphasized to reduce transmission?
A patient presents with a cluster of interconnected furuncles. What is the appropriate terminology to describe this skin condition, and which pathogen is MOST commonly implicated?
A patient presents with a cluster of interconnected furuncles. What is the appropriate terminology to describe this skin condition, and which pathogen is MOST commonly implicated?
Which predisposing factor is MOST associated with the development of Erysipelas in the lower extremities?
Which predisposing factor is MOST associated with the development of Erysipelas in the lower extremities?
A patient presents with painful, erythematous, pus-filled vesicles and honey-colored crusts on their face, along with mild regional lymphadenopathy. What is the MOST likely diagnosis, and what type of bacterial organism is responsible for this?
A patient presents with painful, erythematous, pus-filled vesicles and honey-colored crusts on their face, along with mild regional lymphadenopathy. What is the MOST likely diagnosis, and what type of bacterial organism is responsible for this?
Several children in the same daycare develop small inflamed but painless papules around hair follicles that later break into pustule form. What is the MOST appropriate guidance to give to the daycare staff?
Several children in the same daycare develop small inflamed but painless papules around hair follicles that later break into pustule form. What is the MOST appropriate guidance to give to the daycare staff?
After camping, a teenager presents with an area on their leg that demonstrates warmth, erythema, edema, and tenderness to palpation, but no abscess. History reveals an insect bite a week earlier. What is the MOST appropriate immediate intervention?
After camping, a teenager presents with an area on their leg that demonstrates warmth, erythema, edema, and tenderness to palpation, but no abscess. History reveals an insect bite a week earlier. What is the MOST appropriate immediate intervention?
A patient presents with an erythematous patch on their face, with a sign of streaking. What condition is MOST associated with this streak?
A patient presents with an erythematous patch on their face, with a sign of streaking. What condition is MOST associated with this streak?
An immunocompromised patient is being discharged following treatment for cellulitis. What long-term preventative measure should be discussed to minimize the risk of recurrence?
An immunocompromised patient is being discharged following treatment for cellulitis. What long-term preventative measure should be discussed to minimize the risk of recurrence?
A patient presents with several pustular vesicles. What can be used to treat the MRSA in the nostrils?
A patient presents with several pustular vesicles. What can be used to treat the MRSA in the nostrils?
Flashcards
What is Impetigo?
What is Impetigo?
A superficial bacterial infection of the epidermis that is highly contagious. It presents with honey-colored crusts. Common in children aged 2-5 years.
Clinical Manifestations of Impetigo
Clinical Manifestations of Impetigo
Rash with erythematous vesicles that develops a yellow crust. Very contagious and spreads easily. Fever is rare in non-bullous.
Cellulitis Risk Factors
Cellulitis Risk Factors
Risk factors for cellulitis include being immunocompromised, MRSA, animal bites, diabetes mellitus, or elderly.
Cellulitis Manifestations
Cellulitis Manifestations
Signup and view all the flashcards
What is Erysipelas?
What is Erysipelas?
Signup and view all the flashcards
How does Erysipelas present?
How does Erysipelas present?
Signup and view all the flashcards
What is Folliculitis?
What is Folliculitis?
Signup and view all the flashcards
Manifestations of Folliculitis
Manifestations of Folliculitis
Signup and view all the flashcards
Study Notes
- Cutaneous manifestations of bacterial infections include impetigo, cellulitis, erysipelas, and folliculitis
Impetigo
- Etiology includes Staphylococcus aureus (80% of non-bullous impetigo) and Streptococcus pyogenes (10%)
- Methicillin-resistant Staphylococcus aureus (MRSA) can also be an etiology
- Epidemiology shows it is common in children aged 2-5 years, particularly 90% of bullous impetigo cases
- Susceptibility factors include hot, humid climates, poor sanitation, close quarters, daycare centers, prisons, malnutrition, immunosuppression, overcrowding, diabetes mellitus, and scratching
- Transmission occurs through direct skin contact
- The pathogenesis involves bacterial infection of the superficial layers of the epidermis
- It is highly contagious and can be bullous or non-bullous
- Typically affects the face and other parts of the body and often infects traumatized skin
- Disturbance of the skin barrier provides access to fibronectin receptors for S. pyogenes and S. aureus, which require fibronectin for colonization
- Exfoliative toxin A, produced by S. aureus, causes loss of cell adhesion in the superficial epidermis, leading to self-inoculation to other sites
- Non-bullous impetigo starts as a vesicle or pustule, with multiple vesicles coalescing and rupturing to form a honey-colored crust with an erythematous base
- Bullous impetigo presents with small vesicles that turn into flaccid bullae filled with clear or yellow (or purulent/dark) fluid, surrounded by erythema and edema
- Clinical manifestations include a rash of erythematous vesicles or bullae with a yellow crust, which can be either bullous or non-bullous
- It is pruritic and/or painful, highly contagious, spreads easily, and may involve mild regional lymphadenopathy
- Fever is rare in non-bullous cases
- Diagnosis is primarily clinical, based on history and physical examination
- Serology (ASO titer) is not useful unless acute post-streptococcal glomerulonephritis (APSGN) is suspected secondarily
- Management involves topical or oral antibiotics
- Beta-lactamase-resistant antibiotics are beneficial because they decrease the duration of illness, spread of lesions, and chances of complications affecting the kidneys, joints, bones, lungs, and can prevent acute rheumatic fever
- Systemic antibiotics should be prescribed for bullous impetigo, cases with more than five lesions, deep tissue involvement, systemic signs of infection, lymphadenopathy, or lesions in the oral cavity
- MRSA carriers can be treated with Mupirocin (Bactroban Nasal) applied in the nostrils
- Complications include acute post-streptococcal glomerulonephritis (APSGN), typically occurring 1-2 weeks after a streptococcal infection
- Prevention involves good skin hygiene
Cellulitis
- Etiology includes Group A streptococcus (Streptococcus pyogenes), followed by Staphylococcus aureus
- Atypical bacteria can cause cellulitis such as Pasteurella multocida (dog/cat bite), Vibrio vulnificus (oyster shell cut causing necrotizing fasciitis), and Pseudomonas aeruginosa (diabetic foot ulcer)
- Risk factors include being immunocompromised, having MRSA, animal bites, diabetes mellitus, and being elderly
- Cellulitis is an acute bacterial infection causing inflammation of the deep dermis and surrounding subcutaneous tissue without an abscess or purulent discharge
- Pathogenesis involves breakdown in the skin barrier from various causes allowing normal skin flora and other bacteria to infect the skin
- Methicillin-resistant Staphylococcus aureus (MRSA) can cause cellulitis
- Clinical manifestations include a warm, erythematous area of skin with associated edema and tenderness to palpation, fever, malaise, fatigue, and absence of abscess or purulent drainage
- Diagnosis is primarily clinical and requires two of the four criteria: warmth, erythema, edema, or tenderness
- Blood cultures might be needed for immunocompromised patients
- Treatment involves appropriate antibiotic treatment, such as Cephalexin, or Clindamycin if allergic to beta-lactamase inhibitors
- For cellulitis with MRSA risk factors, Trimethoprim-sulfamethoxazole + Cephalexin can be prescribed
- Cellulitis should start resolving within 24 to 48 hours after initiating antibiotics
- Hospitalization and IV antibiotics may be needed if immunocompromised, with systemic signs/symptoms, or refractory to oral antibiotics
- Overall, cellulitis has a good prognosis
- Complications include systemic inflammatory response syndrome (SIRS) criteria, sepsis, endocarditis, and osteomyelitis
Erysipelas
- Caused by Streptococcus pyogenes (GABHS)
- Immunocompromised and elderly individuals are at higher risk
- It affects the upper dermis and superficial lymphatic system
- Infection starts with skin breaks, and leads to inoculation of the eliciting bacteria
- Portals of entry include surgical incisions, insect bites, and stasis ulcers
- Facial can be caused by a recent infection in the nasopharynx
- Diffuse erythematous, raised, well-demarcated, and often affects the lower extremities, second most common is the face
- Involves upper dermis/superficial, while cellulitis involves deep dermis + subcutaneous tissue
- Presents as a bright red erythematous elevation of the affected skin with well-demarcated borders
- streaking can be involved when superficial lymphatics are involved
- Primarily involves the lower extremities, specifically interdigital toe spaces, and the face
- Diagnosis is clinical, based on history and physical examination
- Lab work-up is not required unless there is a risk of complications
- Treatment involves Amoxicillin or Cephalexin
- Complications include sepsis (rare) and necrotizing infection (rare)
- Prevention involves good skin hygiene and avoiding trauma
Folliculitis
- Staphylococcus aureus is a common cause
- Pseudomonas aeruginosa is associated with hot tub folliculitis
- Ubiquitous and benign, with no predilection for race, age, or sex
- Mostly self-limited
- Risk factors include causing damage to hair follicles from shaving, waxing, wearing tight clothes, contaminated hot tubs/pools, and tight plastic clothing
- Can be spread from person-to-person
- Infection of hair follicles leads to inflammation and formation of pustules or erythematous papules
- Hair follicles are damaged or blocked
- Its prevalence is enhanced when perspiration, trauma, friction, and occlusion of the skin are present
- Shaving is a common cause
- Folliculitis may appear as small inflamed papules around hair follicles with pustules that break and crust
- Distribution is mainly over areas of hair growth
- Diagnosis is folliculitis
- Topical Mupirocin or Clindamycin and Benzoyl peroxide can treat it
- Complications include recurrent or spreading infection
- To prevent it maintain good skin hygiene and is cautious with skin irritants
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
