Perioral Dermatitis Following Upper Respiratory Infection
Most Likely Diagnosis
The most likely diagnosis is perioral dermatitis, a distinctive inflammatory facial eruption that commonly follows upper respiratory infections in prepubertal children and presents with flesh-colored or erythematous papules distributed around the mouth, nose, and occasionally the eyes. 1
Clinical Features Supporting This Diagnosis
Perioral dermatitis typically affects prepubertal children (median age 7 years), with equal distribution between boys and girls. 1
The characteristic distribution is periorificial—perioral, perinasal, and sometimes periorbital—with flesh-colored or erythematous inflamed papules, micronodules, and rare pustules. 1
Systemic symptoms are absent; the child appears well despite the rash. 1
The condition frequently develops after upper respiratory infections, representing an idiosyncratic response to exogenous factors or recent illness. 1
Variable pruritus may be present but is not a defining feature. 1
Key Differential Diagnoses to Exclude
Impetigo
- Impetigo presents with honey-colored crusted lesions, typically on the face and extremities, caused by Staphylococcus aureus or Streptococcus pyogenes. 2, 3
- The absence of honey-colored crusting and the perioral distribution argue against impetigo. 2
Scarlet Fever (Streptococcal Pharyngitis with Rash)
- Scarlet fever requires fever, sore throat, and a sandpaper-textured rash that starts on the trunk and spreads, sparing palms and soles. 2, 4
- A well-appearing child with isolated perioral rash and no fever or systemic symptoms does not meet criteria for scarlet fever. 4
Viral Exanthems
- Roseola (HHV-6) presents with 3–4 days of high fever followed by rash appearing when fever breaks, affecting infants under 3 years. 5
- Erythema infectiosum (fifth disease) features a "slapped cheek" facial rash with subsequent lacy reticular rash on extremities. 2
- The perioral distribution and absence of fever make these viral exanthems unlikely. 2, 5
First-Line Treatment
Discontinue any topical fluorinated corticosteroids if used, and initiate topical metronidazole as monotherapy for mild cases or in combination with oral erythromycin for moderate-to-severe perioral dermatitis in children aged 7 years. 1
Specific Treatment Regimen
Topical metronidazole gel or cream applied twice daily to affected areas is the cornerstone of therapy. 1
For more extensive or persistent disease, add oral erythromycin (age-appropriate dosing, typically 30–50 mg/kg/day divided into 2–4 doses) for 4–6 weeks. 1
If the child was using a potent topical corticosteroid, a low-potency topical steroid (e.g., hydrocortisone 1%) may be used briefly to suppress rebound inflammation and facilitate weaning. 1
Avoid fluorinated topical corticosteroids, as they are a common trigger and can perpetuate the condition. 1, 6
Expected Clinical Course and Follow-Up
Perioral dermatitis waxes and wanes over weeks to months but typically resolves with appropriate treatment. 1
Reassess in 2–4 weeks to confirm improvement; if no response, consider referral to pediatric dermatology. 1
Educate parents that this is a benign, self-limited condition that does not indicate serious underlying disease. 1
Common Pitfalls to Avoid
Do not prescribe antibiotics empirically without considering perioral dermatitis, as this condition mimics bacterial infection but requires different management. 1
Do not continue or initiate potent topical corticosteroids, as they are a primary trigger for perioral dermatitis in children. 1, 6
Do not assume all perioral rashes are impetigo; the absence of honey-colored crusting and the characteristic periorificial distribution distinguish perioral dermatitis. 1, 2
Do not overlook inhaled corticosteroids as a potential trigger if the child has asthma or recent respiratory illness requiring inhaled steroids. 6
Do not test for Group A Streptococcus when the child is afebrile, well-appearing, and lacks pharyngeal symptoms, as this leads to unnecessary antibiotic use. 4