An illness script is an organized mental summary of a provider’s knowledge of a disease (1-3). It represents a clinician’s knowledge about a particular disease, and may be as short as a 3×5 pocket card description for a rare disease, or as long as a book chapter for a commonly encountered illness. Classically, the components of a thorough illness script fall into three main categories: “the predisposing conditions, the pathophysiological insult, and the clinical consequences” (4). Within these categories, illness scripts often include a disease’s pathophysiology, epidemiology, time course, salient symptoms and signs, diagnostics, and treatment. For example, a provider’s illness script for community acquired pneumonia (CAP) may include:
- Infection of the lower respiratory tract
- Most commonly caused by Streptococcus pneumoniae
- Post upper respiratory tract viral infection
- Structural lung disease
- Acute (days)
- Progressively worsens if not treated
- Shortness of breath
- Lobar infiltrate on chest x-ray
- Bacteria in sputum or blood cultures
- Antibiotics typically lead to improvement over days
Building Illness Scripts
The absence of a fever does not exclude the diagnosis of CAP in an elderly patient
A lobar infiltrate on chest x-ray without cardiomegaly or cephalization of vessels is highly suggestive of CAP and makes congestive heart failure less likely.
Chronic obstructive pulmonary disease (COPD) exacerbation and congestive heart failure resemble CAP.