Dermatology Case Studies

A is for Asymmetry

• Asymmetry is characteristic of most skin cancers, however, SCC is generally round, just like cold sores hence difficult to differentiate via this feature alone
• In this case you can see the lesion is relatively symmetrical

B is for Border irregularity

• Both cold sores and SCC can have irregular or hard-to-define borders
• However, cold sores tend to be reasonably flat while SCC can become more raised due to invasion of the subcutaneous tissue and blood vessels
• In this case you can see the photograph shows a raised lesion with an irregular border

C is for Colour variability and/or Changing colour

• A cold sore is generally a few shades of pink with a darker/ golden crust
• SCC can appear similar, however it is important to distinguish the central ulceration seen in SCC lesions from the generalised crusting seen in cold sores while they heal
• In this case you can see a pink-red lesion with some subtle central ulceration and crusting is limited to the periphery

D is for Different

• The presentation of this lesion is different compared to a cold sore, most notably, this includes the fact it has not appeared at the usual site the patient knows he gets cold sores in and the fact there is persistent central ulceration
• A pigmented lesion that is obviously different from the others is sometimes called an 'ugly duckling', 'black sheep', 'lone ranger', or 'odd-mole-out' and must be considered suspicious even if it does not fulfil the ABCDE criteria

E is for Evolving (changing)

• Change in size, colour, shape, or structure may be noted over months to years
• In healthy individuals, a cold sore typically shrinks in size and heals over a short period, regardless of treatment
• Meanwhile, this lesion has increased in size over the month which is a concerning point in the history