Photodynamic therapy (PDT) aftercare

This information is for patients who have had Photodynamic Therapy (PDT) at Spot Check Clinic. PDT is an effective treatment for solar keratoses and some superficial skin cancers. Many patients also notice improvements in skin texture and pigmentation as the treated area heals — a recognised benefit of the treatment process.

Redness, swelling and peeling are common after PDT, but an unexpectedly worsening reaction can need review. The severity of a reaction does not by itself show how well treatment has worked.

What to expect as the skin heals

• First 48 hours — the treated area is highly sensitive to light. Redness and a burning or stinging sensation are common. Some people experience significant discomfort; others notice only mild irritation.
• Days 3–5 — peak inflammation. The skin may become swollen, red and sore. Weeping or small blisters can occur. Contact us if symptoms are severe or worsening unexpectedly.
• Days 6–14 — swelling settles and surface crusts begin to separate. The skin may feel itchy and tight. Do not pick at crusts or peel the skin.
• Several weeks onwards — the skin gradually clears and looks smoother. Residual redness usually fades over several weeks. In some cases, increased pigmentation of the treated area can occur; this often settles over several months.

Light protection — first 48 hours

The photosensitising medication remains active in your skin for approximately 48 hours after treatment. During this period:

• Stay indoors and avoid direct and indirect sunlight, including sitting near bright windows
• If you must go outside, cover the treated area with clothing or a non-stick dressing and wear a broad-brimmed hat
• Physical protection is more important than sunscreen during this immediate window

After 48 hours, continue to avoid sun exposure on the treated area for a further 2–3 days.

What is normal after PDT

• Intense redness and swelling
• Peeling, crusting or flaking of the skin
• Small fluid-filled blisters or pustules — these are usually inflammatory, not infected
• Itching and tightness as the skin heals
• Weeping or raw-looking areas during peak inflammation

Contact the clinic if you notice

• Pain not managed by paracetamol and cool compresses
• Spreading redness with yellow or honey-coloured crusting
• Pustules that are extremely tender to touch
• Fever or feeling generally unwell

Managing your recovery

Pain, itch and swelling

Cool compresses — a clean damp towel or covered ice pack — applied for 10–15 minutes several times daily can help. Paracetamol can be taken for discomfort. If the area is itchy and swollen, antihistamines such as Telfast or Claratyne can help.

Do not take anti-inflammatory medications such as ibuprofen, naproxen or diclofenac. The treatment relies on an inflammatory response and these medications may reduce its effect.

Skin care

Keep the skin hydrated to reduce tightness and itching. Apply a bland moisturiser or petroleum ointment (such as Vaseline, Bepanthen or E45) to the treated area several times daily. Use a gentle soap-free cleanser when washing.

Avoid antiseptics such as Savlon, Dettol or Betadine — these can be toxic to healing skin cells.

Avoid active skin care products including retinols, AHAs and vitamin C until the skin has fully healed.

Cold sores

If you have a history of cold sores on or around your lips, PDT can trigger an outbreak. If we are aware of this history, preventive antiviral medication will be prescribed before your treatment and for several days after.

LED light therapy

LED light therapy may be used several days after PDT to help settle intense inflammation and support the skin’s natural repair process.

Follow-up

A follow-up review is usually scheduled around 4–6 weeks after treatment to assess how well the treated lesions have responded. If lesions persist, further treatment or biopsy may be recommended.

Our doctor or nurse may also contact you in the days following treatment to check on your progress and provide advice if needed. There is normally no out-of-pocket expense for your post-treatment consultation.

If you notice new rough or scaly spots in the future, it is important to have them assessed with a skin cancer check.