Diagnosis of Cellulitis
Diagnosis of cellulitis is usually based on clinical evaluation, but in certain cases, additional tests may be needed to rule out other conditions or assess the severity. Recognising the signs early is crucial, as cellulitis can quickly become dangerous without timely treatment.
1. Medical History and Physical Examination
A doctor will begin by reviewing your medical history and symptoms. They’ll ask when the symptoms started, whether the area has changed in size or appearance, and if there has been recent trauma or injury to the skin. Conditions like diabetes, lymphoedema, or immune suppression are also relevant.
During the physical exam, the healthcare provider will inspect the affected area for:
- Redness, warmth, and swelling
- Pain or tenderness to touch
- Blistering, skin breakdown, or discharge
- Movement limitations or swelling in surrounding joints or limbs
2. Blood Tests | Diagnosis of Cellulitis
While not always necessary in mild cases, blood tests can help confirm infection severity or identify complications. Common tests include:
- Full blood count (FBC): To check for elevated white blood cells
- C-reactive protein (CRP): To assess inflammation
- Blood cultures: To identify if the infection has entered the bloodstream (sepsis)
Elevated markers may suggest a more serious or systemic infection, prompting more aggressive treatment or hospital admission.
3. Wound Cultures
If there is an open wound, ulcer, or blister that is leaking fluid, a swab may be taken to determine which bacteria are present and which antibiotics will be most effective.
4. Imaging
Imaging studies like ultrasound, X-ray, or MRI may be used if the diagnosis is uncertain or if there’s concern about an abscess, deep tissue infection, or bone involvement (osteomyelitis). These are more commonly ordered in patients who don’t improve after initial treatment.
5. Differential Diagnosis
Cellulitis can sometimes be mistaken for other conditions such as deep vein thrombosis (DVT), eczema, contact dermatitis, or venous stasis. A careful diagnosis is essential to avoid inappropriate treatment.
Diagnosis of Cellulitis
Doctors can start the correct antibiotic therapy promptly once they make an accurate diagnosis of cellulitis. This reduces the risk of complications and speeds up recovery.
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