Pharmacotherapeutics of Impetigo

1. Impetigo
Dr. V.S.Swathi
Assistant Professor

2. Definition
• Impetigo is a common infection which affects
superficial layers of epidermis that is highly
contagious and most commonly caused by gram
positive bacteria.

3. Epidemiology
• In the world, impetigo affects more than 160
million children in low to middle income
countries
• In India, it affects impetigo incidence is 5.96%

4. Types
• Primary Impetigo- Bacteria directly affects
normal skin
• Secondary Impetigo- Bacterial infection occurs
at wounded skin

5. Risk factors
• Malnutrition
• Immunesupression
• Overcrowding
• Diabetes
• Poor Hygiene
• Infants and children

6. Triggering factors
• Varicella infections
• Herpes zoster infection
• Scratching
• Lice
• Burns
• Trauma
• Insect bites

7. Etiology
• Staphylococcus aureus
• Methicillin resistant Staphylococcus aureus
• Group A beta-Haemolytic Staphylococcus
aureus
• Streptococcus pyogenes

9. Clinical Presentation
Bullous Impetigo
• Initially small vesicles with clear or yellow fluid
will appear after that they become flaccid bullae
with dark purulent fluid
• Once the bullae ruptures, an erythematous base
with rim of scale remains

10. Non Bullous Impetigo
• Initially multiple vesicles or pustules present
• Once vesicles rupture, then honey coloured crust
forms with purulent exudate
• Rapid spread and satellite lesion formation
occur
• Mild regional Lymphadenopathy is present

11. Ecthyma
• It affects deeper tissues of the skin
• Ulcerative lesions will be present
• Crusts are honey coloured or brownish black
• Lesion may be purulent

12. Complications
• Renal dysfunction
• Septic arthritis
• Scarlet fever
• Sepsis
• Staphylococcal scaled skin syndrome

13. Diagnosis
• Medical history
• Clinical presentation
• Bacterial culture test
• Skin biopsy

14. Non Pharmacological Treatment
• Maintain hygienic conditions
• Cover with bandages
• Counselling

15. Treatment Algorithm

16. Drugs used in treatment of Impetigo
Drug Category Mode of
Action
Dose Adverse affects
Mupirocin Topical
antibiotic
Inhibits
protein
synthesis in
bacteria
2% ointment-BD
for 5 days
 Burning
 Stinging
 Pruritis
 Rash
 Dry skin
Retapamulin Topical
antibiotic
Inhibits
protein
synthesis in
bacteria
1% ointment-BD
for 5 days
 Burning
 Stinging
 Pruritis
 Rash
 Dry skin
Fusidic acid Topical
antibiotic
Inhibits
protein
synthesis in
bacteria
1% ointment-BD
for 5 days
 Burning
 Stinging
 Pruritis
 Rash
 Dry skin

17. Cephalexin Cephalosporin Inhibits cell wall
synthesis in bacteria
250mg-QID-PO for 7 days
in adults
 Anaemia
 Angioedema
 Transaminitis
 Pseudomembranous
colitis
 Dyspepsia
Amoxacillin+
Clavulanic acid
Penicillin+
Beta lactamase
inhibitor
Inhibits cell wall
synthesis in bacteria
+
Decreases resistance by
bacteria towards
penicillin
875/125 mg-BD-PO for 7
days in adults
 Anemia
 Angioedema
 Transaminitis
 Dyspepsia
 Hypersensitivity
Dicloxacillin Pencillin Inhibits cell wall
synthesis in bacteria
250 mg-QID-PO for 7 days
in adults
 Abdominal Pain
 Diarrhea
 Anaemia
 Transaminitis
 Hypersensitivity
Clindamycin Lincosamide
antibiotic
Inhibits protein
synthesis in bacteria
300mg-QID-PO for 7 days
in adults
 Abdominal Pain
 Agranulocytosis
 Diarrhea
 Pseudomembranous
colitis
 Steven Johnson’s
Syndrome

18. Vancomycin Glycopeptide
antibiotic
Inhibits
cell wall
synthesis
in bacteria
1g-BD-IV  Hypokalemia
 Abdominal pain
 Diarrhea
 Urinary tract infection
 Peripheral oedema
Cotrimoxazole Sulphonamide Inhibit
folic acid
synthesis
in bacteria
20mg/kg/day -
BD
 Anorexia
 Peripheral neuritis
 Hyperkaelemia
 Steven Johnson
Syndrome
 Tissue Epidermal
Necrosis
Doxycycline Tetracycline Inhibits
protein
synthesis
in bacteria
100mg-BD-PO
for 7 Days
 Anorexia
 Dental discoloration
 Diarrhea
 Dysphagia
 Enterocolitis

19. Resources
• https://www.bmj.com/content/bmj/324/7331/2
03.full.pdf
• https://www.frontiersin.org/articles/10.3389/fp
ubh.2017.00158/full
• https://bmjopen.bmj.com/content/bmjopen/9/
10/e031527.full.pdf
• https://www.sciencedirect.com/science/article/
pii/S2352647519301169?via%3Dihub
• https://www.karger.com/Article/Pdf/504536