Streptococcus Intertrigo

A 3-week-old boy was referred for evaluation of suspected herpes simplex virus (HSV) infection in the inguinal and pelvic regions. The rash had reportedly worsened since its appearance 2 days earlier and was associated with a foul smell.

The patient was born at term via an uncomplicated vaginal delivery after a normal gestation. He had been circumcised with a sterile disposable device on day 2 of life. He had been formula-fed since birth and was otherwise healthy.

Physical examination revealed an alert, well-nourished newborn who was fussy but consolable. Temperature was 38.1?176-129?C (100.6°F), respiration rate was 48 breaths per minute, and heart rate was 152 beats per minute. Weight, height, and head circumference were above the 50th percentile for age. The infant had a beefy red, moist, denuded malodorous rash with macerated, irregular borders in the right inguinal fold; he also had erythematous, maculopapular satellite lesions with pustules over the pelvic region, lower abdomen, and the medial aspect of the upper legs (Figure 1). The remaining examination findings were normal.

The differential diagnosis included irritant diaper dermatitis, candidal intertrigo, group A b-hemolytic Streptococcus (GABHS) intertrigo, impetigo, staphylococcal pustulosis, and HSV infection.

The patient was hospitalized and treated empirically with cephalexin and intravenous acyclovir because of the possibility of bacterial and HSV infections and because most of the staphylococcal disease in the community at the time was methicillin-sensitive. Swabs of the conjunctiva, mouth, nasopharynx, and rectum were obtained for herpes cultures. Specimens of the skin vesicles, urine, stool, blood, and cerebrospinal fluid (CSF) were analyzed.

Cultures of the vesicles grew 98% GABHS that was sensitive to penicillin and cephalosporins. The antibiotic therapy was continued. Within a few days, the rash began to clear and the fever and fussiness resolved. Five days after admission, cultures and polymerase chain reaction assay of CSF were negative for HSV and the patient was discharged.

NEONATAL INTERTRIGO

Intertrigo results from constant moisture within the skin folds and skin-on-skin friction. Infants are especially susceptible to this inflammatory condition because of their flexed posture, relatively high percentage of body fat, and short neck.

The diaper area is an ideal environment for intertrigo. The persistent dampness and lack of circulating air reduces the skin's defense against physical, enzymatic, and chemical breakdown. In diaper dermatitis, lipases and proteases in feces and urine create an alkaline environment that causes further skin damage. This fosters infection with fungi, bacteria, or both.¹ In addition to systemic symptoms (such as fever), secondary infection with GABHS may be identified by a foul smell, satellite lesions, weeping tissue, and confluent erythema.

In patients with intertrigo, always consider secondary infection with Candida albicans, GABHS, or Staphylococcus aureus (with or without GABHS). Mixed infections of intertriginous areas with Pseudomonas aeruginosa, Proteus vulgaris, and Proteus mirabilis have also been reported.²

DIFFERENTIAL DIAGNOSIS

Irritant diaper dermatitis is a common problem in neonates and infants. Children typically have erythema and scaling, which may extend from the umbilicus to the thighs. Involvement of the buttocks, perine-um, lower abdomen, and proximal thighs with sparing of the creases is common.

Candidal intertrigo presents with sharply demarcated beefy red plaques that often involve the skin folds (Figure 2). Pustulovesicular satellite lesions are a common feature of candidal infections.²

GABHS intertrigo is clinically similar to candidal intertrigo; both conditions appear in the same areas. However, GABHS intertrigo has a weepy appearance and a foul smell, which is the main distinguishing characteristic.²

Impetigo also thrives in damaged skin. It commonly presents as a tender red rash with pustules and other satellite lesions. The condition is caused by GABHS or S aureus--or frequently both. If bullae are present, S aureus is most likely the culprit. The release of epidermolytic toxins that target cells in the superficial epidermis causes loss of cell- to-cell adhesion, which leads to bullae formation. Bullous impetigo (Figure 3) is on the spectrum of staphylococcal scalded skin syndrome.³

Staphylococcal pustulosis may occur as early as the second day of life. Lesions commonly appear in moist areas with opposing surfaces, such as the groin/diaper area, axillae, and neck folds (Figure 4). Although children with staphylococcal pustulosis are typically otherwise healthy, they must be treated and followed closely because of the rise of methicillin-resistant S aureus (MRSA) disease, which can be associated with high morbidity.

HSV infection must be considered when evaluating skin lesions in infants who are younger than 6 weeks, because of the high morbidity and mortality associated with the disease in this age group. This diagnosis was unlikely, however, given the appearance and location of the rash.⁴ HSV lesions are generally groups of vesicles on an erythematous base and typically appear on the scalp and face.⁵

MANAGEMENT

Complete resolution of intertrigo can be expected with proper treatment. For simple intertrigo or diaper dermatitis, a barrier cream is the agent of choice. Candidal intertrigo is susceptible to antifungal agents, such as ketoconazole or nystatin.⁶

When secondary bacterial infection is suspected, cultures should be obtained for drug sensitivities. Until laboratory results are available, empiric therapy covering S aureus and GABHS should be started. If your community has a high rate of MRSA, consider empiric therapy with clindamycin, although it is less effective for methicillin-sensitive S aureus.⁶ Trimethoprim/sulfamethoxazole works well for MRSA infection but is ineffective against GABHS infection and is contraindicated in infants younger than 2 months. An antibiotic cream, such as mupirocin, should also be applied 3 times a day.

Topical anti-inflammatory preparations, such as 1% hydrocortisone cream, may help alleviate any residual erythema after intertriginous infection.² If intertrigo fails to respond to treatment within a few days, consider an alternative diagnosis.

KEY POINTS FOR YOUR PRACTICE

Intertrigo is a common entity in infants. When evaluating a child with intertrigo that failed to resolve with barrier treatment and Candida superinfection therapy, consider the possibility of GABHS intertrigo, especially when the rash has a foul smell and weepy appearance. *

References:

REFERENCES:

1.

Agrawal R, Sammeta V. Diaper Dermatitis. eMedicine Web site. Available at: http:// www.emedicine.com/ped/topic2755.htm. Accessed October 22, 2007.

2.

Honig PJ, Frieden IJ, Kim HJ, Yan AC. Streptococcal intertrigo: an underrecognized condition in children.

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3.

Cole C, Gazewood J. Diagnosis and treatment of impetigo.

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2007;75:859-864.

4.

Paller AS, Mancini AJ.

Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence.

3rd ed. Philadelphia: Elsevier; 2006:37-38.

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Colletti JE, Homme JL, Woodridge DP. Unsuspected neonatal killers in emergency medicine.

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Janniger CK, Schwartz RA, Szepietowski JC, Reich A. Intertrigo and common secondary skin infections.

Am Fam Physician.

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