My Patient has Cellulitis - are they suitable for OPAT? You have decided that your patient is suitable for OPAT based on standard criteria. Now you must determine that your patient's condition is suitable for OPAT. Cellulitis is a condition characterized by features of superficial skin infection associated with systemic upset. Typically the patient presents with an erythematous swollen area of skin, usually with systemic upset of fevers, generally unwell, to varying degrees of severity. It is clinically important to distinguish cellulitis from other forms of skin and soft tissue infection e.g. necrotising fasciitis. Eron LJ (2000) devised a classification system of skin and soft tissue infections to aid diagnosis and treatment and this is a useful tool in determining whether a patient is suitable for discharge home to an OPAT programme. Essentially if a patient is either Class 1 or 2, they may be candidates for OPAT, however many of these patients will respond to oral antibiotics. If they fail to do so, and depending on the clinical severity of the infection, in conjunction with the assessment by the treating physician, will determine whether iv antibiotics are required. Patients who are in class 3 or 4 are not initially candidates for OPAT, but may become candidates for OPAT during the course of their hospitalization after an initial period of stabilization. Class 1 Patient neither have any features of systemic infection nor any of the co-morbidities listed below.
Class 3 Patients either Are clinically unstable e.g. have
Necrotising fasciitis is a deep-seated soft tissue infection involving the deep fascia tissue, that typically presents initially with a systemically unwell patient and a rapidly evolving skin infection. Early in the course of the infection the external skin findings may be not as significant as expected given the severity of pain and systemic upset. However very quickly, the infection spreads and the systemic signs of inflammation worsen rapidly with hypotension, tachycardia, significant leukocytosis, and multiorgan failure. The affected region typically becomes mottled and bullous, with crepitus and gangrene evident as a very late finding. This is usually a clinical diagnosis although a plain film may demonstrate air bubbles, and an MRI is the most useful radiological investigation. Urgent assessment by plastic syrgery or general surgery in addition to broad spectrum antibiotics as per your hospital's protocol are required immediately. What Antibiotics should I give to my patient with cellultis receiving OPAT and how long should they receive OPAT? You have assessed your patient and you are happy that they are suitable for OPAT. The following are recommendations from the IDSI (infectious Diseases Society of Ireland) are for the treatment of cellulitis in an OPAT setting. The determining factors are good antibiotic stewardship, ease of use, penicillin allergy and known previous microbiology results. The typical duration of therapy for cellulitis should be 10-14 days, but iv antibiotics should be discontinued and changed to po antibiotics once there is a significant clinical improvement in the condition, which is typically at 3-4 days. This change must only happen after a clinical assessment in the OPAT clinic. Penicillin allergy Please ensure that any allergy history is recorded carefully and accurately. If there is any doubt please try to contact the patients' GP or pharmacy to determine their antibiotic exposure recently. Many patients who report a 'penicillin allergy' have often received a penicillin-type antibiotic from their GP or a hospital in the recent past unknown to themselves, so an accurate history is critical. For patients who have a history of a Type 1 Hypersensitivity reaction to a penicillin i.e. urticaria, anaphylaxis, significant rash immediately after taking penicillions, they should not be rechallenged with a penicillin or a cephalosporin. For those patients with a Non-type 1 Hypersensitivity reaction to penicillin i.e. a mild rash, or a rash >72hours after the antibiotic started, they can be rechallenged with a cephalosporin. Obviously symptoms of GI upset etc. are not considered to be an allergic reaction.