Impetigo

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

8. 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

9. 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

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

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

12. Diagnosis Medical history Clinical presentation Bacterial culture test Skin biopsy

13. Non Pharmacological Treatment Maintain hygienic conditions Cover with bandages Counselling

14. Treatment Algorithm

15. 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

16. 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

17. 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

18. Resources https ://www.bmj.com/content/bmj/324/7331/203.full.pdf https://www.frontiersin.org/articles/10.3389/fpubh.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