Suspect cellulitis if the cheek or some other part of the face in a child is red and hot or one eye is swollen shut (picture 1).
Differential diagnosis
Dacryocystitis, severe conjunctivitis, frostbites and allergic reactions
A patient with cellulitis will present with fever, increased serum CRP concentration and leucocytosis.
Development and causative agents
Cellulitis of a cheek is usually haematogenic with no predisposing factors.
Of all cases of cellulitis around the eye socket, nine out of ten will be periorbital, i.e. the infection is located in the eyelids and the periocular tissue.
Periorbital cellulitis develops either as a consequence of conjunctivitis or a break in the skin or by haematogenic spread of infection.
Orbital cellulitis is much more rare. In orbital cellulitis, the patient's eyesight may be endangered when the eye is bulged outwards and the optical nerve distended by the abscess formed in the orbital cavity.
Orbital cellulitis is usually developed as a complication to sinusitis.
If orbital cellulitis is suspected, MRI or CT scan of the orbita should be considered. Differentiation between orbital and periorbital cellulitis may be difficult without imaging studies, especially in small children.
The causative agent in cellulitis which originates from a skin break is often Staphylococcus aureus and streptococci. Particularly after chickenpox the causative agent often is Group A streptococcus. In haematogenic cellulitis, the most common causative agents are pneumococci.
The introduction of the Hib vaccine has practically eradicated Haemophilus-induced cellulitis.
Treatment
Fever or laboratory results suggestive of a bacterial infection warrant an urgent referral to hospital.
Treatment consists of parenteral cefuroxime 100 mg/kg/day after blood cultures have been taken.
References
Hauser A, Fogarasi S. Periorbital and orbital cellulitis. Pediatr Rev 2010;31(6):242-9. [PubMed]
Fenster DB, Renny MH, Ng C et al. Scratching the surface: a review of skin and soft tissue infections in children. Curr Opin Pediatr 2015;27(3):303-7. [PubMed]