Skin Swab Test for Infection Diagnosis in London

What is a Skin Swab Test?

A skin swab test is a simple, painless diagnostic procedure where a sterile swab is rubbed against the affected skin to collect a sample of cells, discharge, or microorganisms. The swab is then sent to the laboratory for microscopy, culture, and sensitivity (MC&S) — enabling identification of bacteria, viruses, or resistant organisms causing infection.

At Skinhorizon Clinic, swab testing is performed under consultant supervision. This ensures that samples are collected correctly, interpreted alongside your clinical history, and used to guide the most effective treatment — avoiding unnecessary or ineffective antibiotics.

When is it recommended?

A skin swab test is recommended whenever an infection is suspected and treatment decisions need to be evidence-based. Typical scenarios include:

• Boils, abscesses, or cellulitis not responding to initial antibiotics
• Recurrent impetigo or infected eczema
• Suspicion of resistant organisms such as MRSA
• Blistering or ulcerated lesions where viral infection is possible (e.g. herpes simplex, varicella)
• Weeping wounds or poor healing skin lesions
• Scalp infections with pus or crusting

By identifying the exact organism, we avoid unnecessary broad-spectrum antibiotics and select the most effective targeted therapy.

How it works

1. Preparation: The affected area is gently cleaned of excess debris or ointment if needed.
2. Sample collection: A sterile swab is rubbed against the lesion, ulcer, or exudate to collect organisms.
3. Laboratory testing: The swab is sent for microscopy, culture, and sensitivity testing.
4. Optional viral PCR: For suspected herpes or varicella, swabs may be sent for molecular testing.
5. Consultant review: Results are interpreted alongside your clinical history and symptoms.

What can it help diagnose?

• Bacterial infections: Staphylococcus aureus (including MRSA), Streptococcus, Pseudomonas
• Viral infections: Herpes simplex virus (HSV), Varicella zoster virus (VZV)
• Superinfection: Secondary bacterial infection complicating eczema or wounds
• Antibiotic resistance: Determines which antibiotics are effective for your infection

This ensures treatment is accurate and avoids both under-treatment and overuse of antibiotics.

Preparation

• Avoid applying topical antibiotics, antiseptics, or creams on the area for 24 hours before the test.
• Do not clean or disinfect the lesion just before your appointment, as this may reduce yield.
• Bring a list of current and recent medications, especially antibiotics.

Safety & limitations

A swab test is safe, quick, and painless. Limitations include: sometimes swabs detect colonising organisms not causing disease, or samples may fail to grow in culture. In such cases, results are always interpreted in the context of your symptoms and examination.

Results & follow-up

Preliminary microscopy results may be available within 24 hours, while culture and sensitivity typically take 2–5 days. Viral PCR results may take longer depending on the laboratory. Your consultant will review results with you and provide a tailored management plan, which may include topical or oral treatments, wound care, or referral if more complex infection is suspected.

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Disclaimer: Diagnostic tests at Skinhorizon are provided only where clinically appropriate and must be interpreted by a qualified healthcare professional. Results alone do not replace a medical diagnosis, and further consultation may be required.