Table 2.

Risk Factors for Necrotizing Fasciitis Among Cases and Controls

VariablesCasesControlsPOdds Ratio
(95% Confidence Interval)
No. (%)Mean (Range)No. (%)Mean (Range)
Medications (prehospitalization)
 Ibuprofen9 /19 (42)4 /26 (15)5.0 (1.03, 26.6)
 Acetaminophen15 /19 (79)22 /26 (85).7 (.1, 4.3)
 Diphenhydramine13 /19 (68)13 /26 (50)2.2 (.5, 9.1)
 Antibiotics6 /19 (35)6 /26 (23)1.5 (.3, 7.1)
 Calamine lotion10 /18 (56)18 /26 (69).6 (.1, 2.3)
Preexisting medical problem 4 /19 (21)5 /29 (17)1.3 (.2, 7.0)
Out-of-home care for preschool age kids3 /6 (50)7 /9 (78).64 (.1, 4.6)
Infectious contacts/exposures
 Contact with a person with sore throat,
strep throat, skin infection
5 /19 (26)7 /26 (27)1.0 (.2, 4.5)
 Recent strep infection 2 /19 (11)1 /27 (4)3.1 (.1, 187.3)
 Household varicella exposure§ 7 /18 (39)9 /26 (35)1.2 (.3, 4.9)
 Varicella lesions in area of secondary infection19 /19 (100)26 /27 (96)undefined
Bathing
 Baths 1.9 (1–3)1.9 (0–8).8
 Oatmeal/oat based products 10 /18 (56)19 /26 (73).5 (.1, 2.0)
 Baking soda 7 /18 (39)8 /26 (31)1.4 (.3, 6.0)
Duration (days) of secondary symptoms before
hospitalization
 Pain, swelling, erythema, splinting1.1 (0–3)1.8 (0–21).37
 Secondary fever after onset of varicella1.6 (0–6)2.3 (0–20).77
Microbiology
 Group A Streptococcus isolation# 16 /19 (84)8 /29 (27)14.0 (2.8, 89.3)
 Another organism isolated** 2 /19 (10)3 /29 (10)
 No organism isolated1 /19 (5)18 /29 (62)
  • * Unadjusted odds ratios are reported.

  • Asthma, eczema, frequent otitis/sinusitis, developmental delay, mild hemiplegia.

  • Within 2 weeks of the onset of the symptoms associated with the secondary infection.

  • § As the presumed source of varicella.

  • Per day, during the varicella rash.

  • In the bath water used during the varicella rash.

  • # Three cases and 1 control also had Staphylococcus aureus isolated in addition to group A streptococcus.

  • ** Including S aureus, group B streptococcus,Haemophilus influenzae.