A clinico-bacteriological study of pyodermas in pediatric population

INTRODUCTION

Pyoderma is the bacterial infection of skin and its appendages.¹ It is highly prevalent in pediatric age group.² Multiple factors like malnutrition, hot–humid climatic conditions, poverty, overpopulation and poor personal hygiene are the main culprits for making pediatric population more prone to both primary and secondary pyodermas.³ Primary pyodermas include superficial bacterial infections like impetigo, folliculitis, furuncle, carbuncle etc. Whereas secondary pyodermas in children occur in diseased skin such as atopic dermatitis, scabies, insect bites etc. The injudicious use of antibiotics has resulted in emergence of resistant pyodermas.⁴ Despite discoveries of many new antibiotics, it is becoming difficult to curb the menace of resistant pyodermas. Thus it is mandatory to study the clinical and antibiotic spectra of common causative organisms. With this perspective, the present study was conducted to identify the bacteriological profile of pyodermas and their current susceptibility pattern in pediatric age group.

METHODS

In this cross sectional study on pyodermas, we evaluated 456 cases of pyoderma in pediatric population attending dermatology outpatient department of Sri Guru Ram Das Medical College over the period of 8 months from February 2016- October 2016. All cases of primary and secondary pyodermas in age group <15 years were included. Cases with history of any antibiotic use within last 7 days were excluded from the study. After thorough clinical examination of the skin lesions, under strict aseptic conditions, exudate from the lesions was collected with sterile swab and transported immediately to microbiology lab for further processing.

For isolation and antibiotic susceptibility of bacteria, following procedures were done on the sample:

1) Gram staining.

2) Culture on various media like – nutrient agar, blood agar and Mc Conkey agar.

3) Antibiotic susceptibility testing using Kirby-Bauer disc diffusion method.⁵

RESULTS

Out of 456 cases of pyodermas in children, most cases (31.7%) were seen in the age group of 4-7 years followed by 12-15 years of age (26.5%). Males outnumbered females (M:F=1:7). Higher proportions (60.6%) of pyodermas were present in children belonging to lower socio-economic status. History of overcrowding was present in (57.2%) of pyoderma cases (Table 1).

*Kuppuswami classification;**persons per bedroom >2 persons.

On categorisation of different pyodermas, primary pyodermas (60.3%) were more prevalent than secondary pyodermas (39.6%). Out of the primary pyodermas, impetigo was the most common (23.9%) followed by furunculosis (11.1%). Infected scabies (14.9%) was most frequently encountered cause of secondary pyoderma followed by infected atopic dermatitis (8.9%) (Table 2). Staphylococcus aureus (49.5%) was the most common organism isolated from these cases followed by Streptococcus (29.8%) (Table 3).

Majority of these gram positive organisms were sensitive to antibiotics like amoxiclav, ampicillin and linezolid. Whereas, amikacin, ceftriaxone and tobramycin remained antibiotic of choice for gram negative pyodermas caused by Escherichia coli (E. coli) and enterococcus (Table 4).

DISCUSSION

Pyoderma is a common presenting complaint for most dermatological consultations in pediatric age group.² Different patterns of primary pyodermas encountered include impetigo, folliculitis, furuncle, carbuncle, abscess, periporitis etc. Out of these, impetigo (23.9%) outnumbered all other entities in the present study. This finding is in concordance to various other studies where incidence of impetigo was (19.67%- 24.2%).^3-7 Whereas, in another study done on adult population commonest pattern oberserved was folliculitis.⁷ Scabies, molluscum contagiosum, atopic dermatitis with secondary infection are the common secondary pyodermas encountered in children.⁸ Incidence of secondary pyodermas was higher (39.6%) in the present study as compared to other studies done on mixed or adult population.^6,8 Present study correlated well with the various predisposing factors³ and their association with pyodermas as higher prevalence (81.9%) of bacterial skin infections was observed in children belonging to lower socioeconomic class. Pyodermas are seen more frequently in first decade of life as reported in many studies.^7-9 Similarly, most cases in this study (31.7%) were seen in children belonging to age group 4-7 years followed by 12-15 years. In this study, males were affected more frequently than females as reported by others.⁵ Recurrent pyodermas in children is becoming troublesome day by day due to increased antimicrobial resistance and changing pattern of microbiology of pyodermas.¹⁰ Hence it is important to perform culture and susceptibility tests and treat accordingly with adequate dosage and duration of appropriate antibiotic. In present study, all cases were subjected to gram staining and culture before starting any empirical treatment with antibiotics. On gram staining majority of organisms (93.3%) were gram positive with S. aureus as most common isolate (49.5%) followed by Streptococcus. These finding were in concordance with other studies where Staphyloccus was isolated in (40%) cases.^11-14 Thus, currently there is a shift from streptococcus to S. aureus as the leading cause of pyoderma.¹¹ Among gram negative organisms (6.7%) most cases were due to E. coli (3.1%). This finding is similar to other studies.^10-13 Culture results were negative in 11 patients which is similar to other studies.^11-15 Over the counter availability of antibiotics and their inadvertent use facilitates development of resistance. In this study, strains of coagulase positive S. aureus and streptococcus were susceptible to ampicillin, amoxiclav, linezolid, ceftriaxone and cefotaxime whereas low susceptibility was observed to ofloxacin and levofloxacin. Coagulase negative strains of S. aureus were largely susceptible to penicillin group of antibiotics. On the other hand, gram negative isolates were highly susceptible to ceftriaxone and newer aminoglycoside group of antibiotics like tobramycin and amikacin. To conclude, knowledge regarding the causative organisms of various pyodermas and their susceptibility pattern helps in avoiding injudicious use of antibiotics.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

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