Furunculosis

1. Furunculosis
Furunculosis is a localized form of otitis externa resulting from infection of a single hair follicle.Hair
follicle are only present in the lateral segment of the external auditory canal. Furunculosis is
therefore ,confined to the lateral canal. As the infection progresses a pustule forms & this
progresses to local abscess formation.
Diagnosis
The affected ear is extremely painful, the pinna & tragus are tender on palpation. Otoscopic
examination usually establishes the diagnosis. Oedema & inflammation is restricted to the lateral
segment of the canal with relative medial canal & TM.
If infection is advanced, the abscess may be pointing or have discharged already. If the oedema &
celullitis spreads to the post-auricular crease, the condition may mistake for acute mastoiditis.
Aetiology & epidemiology
Staphylococcus aureus is the most common organism causing furunculosis. (all body sites impetigo &
scalded skin syndrome).
Sporadic cases of furunculosis in context of local risk factors heat, humidity, trauma & maceration.
Colonization of the external nares & less commonly perineum causes recurrent furunculosis.
Severe conditions appear to be associated with recurrent furunculosis include
hypogammaglobulinaemia& DM.
Outcomes
If untreated, progress to abscess then discharge to EAC.Adequate drainage the infection will resolve
spontaneously. Infection may spread to deeper plain pinna, post-auricular skin, parotid gland.
Repeated infection can cause permanent scarring , fibrosis &stenosis of EAC.
Management options
Oral /systemic antibiotics.(penicillinase-resistant penicillin, macrolide, cephalosporin, or quinolone)
Topical treatment; (antibiotic, astringents hygroscopic dehydrating agents)
Incision & drainage.
Oral antibiotic recommended in early stage of disease. Glycerol & Ichthammol solution is
hygroscopic & antistaphylococcal action.Aluminium acetate is an astringent & hygroscopic.
For recurrent furunculosis option includes;
1)Eradication therapy with nasal mupirocin
2)Eradication therapy with oral flucloxacillin for 14 days.

2. 3)Bacterial interference therapy: Deliberately implanting a non-pathogenic strain ( strain
502A is the most popular) to recolonize the nares & skin. Correction of specific biochemical
abnormalities (hypoferraemia, low serum zinc) may lead to marked reduction of recurrent
infections.
(Comparative study of topical antibiotic/steroid drops, i.e Sofradex versus glycerol/icthamol and /or
aluminium acetate solution.)