Recurrent pyoderma like impetigo with or without underlying dermatological disorders or immunodeficiency are common in infants and children all over the world and constitute one of the prime causes of hospital attendance in children.³ Antibiotic resistance has become a clinically important consideration in many infections and Methicillin Resistant Staphylococcus aureus (MRSA) infection, which has been a nosocomial problem for years is now a common community acquired skin infection.⁴ It would be ideal to do culture and sensitivity tests before prescribing antibiotics, but as this is not always feasible studies should be conducted to determine the aetiological agents and antibiotic resistance.⁵

In the current settings, there are no appropriate studies regarding the epidemiological and clinical aspects of childhood impetigo in our society. Also, the studies regarding the exact aetiological agents and their antibiotic susceptibility are not well studied. At this juncture, it was decided to undertake a study to correctly elucidate the epidemiological, clinical and bacteriological aspect of primary pyodermas mainly in children. This study was undertaken with the following aims-

1. To study the clinical profile of primary pyodermas in children.
2. To study the bacteriological profile and antibiotic sensitivity.

Materials and Methods

This study was a descriptive study undertaken in the Department of Dermatology and Venereology, Medical College Hospital, Thiruvananthapuram, South India for a period of one year. The sample population included children between 1 to 12 years who attended the outpatient wing of the department with clinical diagnosis of primary pyoderma. The sample size anticipated was 100. All children with primary pyoderma who were started on topical and systemic antibiotics were excluded. Informed consent was obtained from the parents. A detailed history was taken including socioeconomic status, personal hygiene, history of debilitating illnesses and history of medications. The main investigations included complete blood count, liver and renal function tests, antistreptolysin O titre, random blood sugar, 24-hour urine protein and gram stain and culture and sensitivity of pus from the lesions. Pus culture was done on blood agar and MacConkey’s agar with incubation at 37⁰ C for 48 hours. Organisms grown were identified based on the basis of their morphology, cultural characteristics and biochemical reactions according to the standard methods. Sensitivity of the organisms to antibiotics was tested on Mueller-Hinton agar and by disc diffusion technique using Kirby-Bauer method.

Statistical analysis of the data was done using an appropriate computer software and the data was expressed in frequency and percentage. Chi-square test was used to assess statistical significance and a ‘p’ value of < 0.05 was taken as statistically significant. Kappa co-efficient was used to measure the agreement between the two diagnostic tools, Gram staining and culture. The scale of interpretation of the measure of agreement based on kappa values were as follows:

Results

The study population included 100 patients belonging to the age group of 1 to 12 years of both sexes, who attended the outpatient wing of the Department of Dermatology and Venereology of Medical College, Thiruvananthapuram. The study period was one year. The mean age of the study population was 4.62 years; 56 children belonged to the age group of 1 to 4 years and 44 children belonged to the age group of 5 to 12 years; 70 patients were males and 30 were females. Majority of the children (64) belonged to the lower socio-economic group according to the Kuppuswamy scale of socioeconomic status and 36 children belonged to the middle socioeconomic stratum. Nutritional status as assessed by the Indian Association of Paediatric norms showed adequate nourishment in 76 patients and malnourishment in 24 patients. Personal hygiene as assessed by the habit of daily bathing and changing clothes showed good personal hygiene in all the patients. Predisposing factors for bacterial infections were not observed in the majority (96%), while 2 children were atopic and another 2 children had nephrotic syndrome.

Focus of infections were noticed in 38 patients, which included caries teeth in 14 patients, tonsillitis in 10 patients, upper respiratory infection in 6 patients and otitis media in 4 patients. Otitis media and caries teeth were present in 2 children and otitis media with upper respiratory tract infection was seen in another 2 children. There were no foci of infection in the majority of the patients (62%) (Table 1).

Regional lymphadenopathy was seen in 52 patients and in the remaining 48 patients it was absent. It was most commonly observed in 40 patients with impetigo contagiosa.

Commonest site of skin lesions was extremities in 36 patients followed by head and neck in 20 patients and a combination of both these sites in 22 patients. Both trunk and extremities were involved in 12 patients (Table 2).

Examination of all the systems were normal except that 1 child had nephrotic syndrome and another one had a past history of nephrotic syndrome.

Clinical Diagnosis

The commonest type of primary pyoderma was impetigo seen in 80 cases. Among this impetigo contagiosa was the diagnosis in 76 patients and bullous impetigo in 4 patients. The other diagnoses were folliculitis in 10 patients, furuncle in 8 patients and ecthyma in 2 patients (Table 3).

Investigations

Routine blood investigations showed leucocytosis in 42 cases, neutrophilia in 18 cases, lymphocytosis in 70 cases and elevated ESR in 42 cases. ASO titre was positive in 2 patients, both patients having impetigo contagiosa and one patient had an associated tonsillitis also. Renal function tests were normal in all the patients. Routine urine examination showed albuminuria in 4 patients and urine sugar 1.5% in 1 patient; 24-hour urine protein estimation was done in all patients and was within normal range in all patients.

Gram staining for organisms was positive in 78 cases. All these patients had gram positive cocci and one patient showed gram negative bacilli along with gram positive cocci. Polymorphonuclear leucocytes as pus cells were seen in 82 cases and in 64 of these patients showed pus cells along with gram positive cocci.

Out of all the 100 cases, culture was positive in 84 cases and it was sterile in 16 cases after 48 hours of incubation. Among the culture positive cases 72 cases had isolation of single organism and 12 cases had mixed growth. Staphylococcus aureus was the commonest organism isolated in 68 cases (80.95% of the culture positive cases). Streptococcus pyogenes and Escherichia coli were isolated in 2 cases each (Table 4).

Out of the 68 isolates of Staph. aureus, 60 were sensitive to methicillin (71.43%) and the remaining 8 were methicillin resistant Staph. aureus (9.52%). Among the 12 cases of mixed organism isolates, Staph. aureus was isolated along with Streptococcus pyogenes in 4 cases and with Pseudomonas aeruginosa and Klebsiella sp. in 2 cases each.

Correlation of culture with clinical diagnosis

Methicillin sensitive Staph. aureus was the most common organism isolated from impetigo contagiosa lesions in 50 cases (67.89%) followed by methicillin resistant Staph.

aureus in 6 cases (7.89%), a combination of Staph. aureus and Streptococcus pyogenes in 4 cases (5.26%) and Streptococcus pyogenes alone in 2 cases (2.63%). Out of the 4 bullous impetigo cases, Staph. aureus was isolated from 2 cases and mixed organisms from 2 cases. Out of the 10 cases of folliculitis, methicillin sensitive Staph. aureus was the most common isolate in 4 cases (40%) and MRSA, E. coli and mixed organisms in 2 cases each. Among the 8 cases of furuncles, Staph. aureus was isolated from 4 cases (50%) and the culture was sterile in the remaining 4 cases. The culture was sterile in both cases of ecthyma (Table 5).

Antibiotic Sensitivity Pattern of Culture Organism

Staph. aureus was sensitive to cloxacillin in all the 68 cases (100%), first generation cephalosporin in 64 cases (94.11%), amikacin in 50 cases (73.53%), gentamicin in 40 cases (58.82%) and erythromycin in 16 cases (23.53%). It was resistant to penicillin in 66 out of the 68 cases (97.06%), to erythromycin in 52 cases (76.47%), to amikacin in 18 cases (26.47%), to gentamicin in 28 cases (41.18%) and 1^st generation cephalosporin in 4 cases (5.88%). MRSA was resistant to cloxacillin, penicillin and first generation cephalosporin in all the 6 cases (100%) and to gentamicin in 4 cases (66.67%). E. coli was resistant to ciprofloxacin, first generation cephalosporin and ampicillin (Table 6).