Frontal Bone Osteomyelitis

Synonyms: Pott's Puffy Tumour (PPT), Frontal Bone Osteomyelitis, Osteomyelitis of the Calvarium^1,2

• This is frontal bone osteomyelitis with a subperiosteal (extradural) abscess.
• It usually represents an anterior extension of a frontal sinus infection or as a complication of a compound skull fracture.
• It can also be a complication of mastoiditis and has been reported following an insect bite.³
• Streptococcus milleri group are the commonest pathogens.

• Headaches
• There may be localised swelling
• Fever
• Nuchal rigidity
• Altered mental state (from subtle changes, confusion or complete coma)
• Focal neurological signs e.g. seizures⁴

Since the advent of antibiotics, Pott's puffy tumour⁵ has been only rarely reported (mostly in children and adolescents) but recently has been described following intranasal and inhaled cocaine or methamphetamine abuse,^6,7 and as a complication of dental sepsis.⁸

CT scan (with and without contrast) or MRI scan.⁹ CT scan may reveal bone erosion and evidence of rim enhancing abscess formation. There may be intracranial involvement e.g. fluid collection and CT/MRI may also help in this.

Admission with removal of the infected bone and prolonged intravenous antibiotics (e.g. for six weeks). Antibiotics are usually of the penicillin group e.g. high dose IV benzylpenicillin for 3 weeks followed by 3 weeks of oral amoxicillin. However, all cases should be discussed with the local microbiologist and antibiotics should be altrered once sensitivities are known.

• Extension of infection e.g. brain abscess¹⁰
• Meningitis
• Epidural empyema
• Subdural empyema

Percival Pott (1714-88) was a London surgeon (St Bart's) who also gives his name to Pott's disease of the Spine (spinal tuberculosis - scrophula), fracture dislocation of the ankle (Pott's fracture) and was first to describe an industrially acquired disease: cancer of the scrotum in chimney sweeps.¹¹