Clinical features

• patients are middle-aged or elderly:
  • more common in outdoor workers e.g. fishermen
  • more common in fair-skinned people who live in tropical or sub-tropical regions e.g. Southern USA & Australia
• red, scaling papulue or plaque on a sun-exposed area (1)
• skin lesions bleed easily with minor trauma
• typically, patients give a history of a lesion that loses its scale but then recurs

There are six types of actinic keratosis that can be recognized histologically: hypertrophic, atrophic, bowenoid, acantholytic, pigmented, and lichenoid (1,2).

Reference

1. Seaton E, Madan V. Benign keratinocytic acanthomas and proliferations. In: Barker J, Griffiths C, Bleiker T, eds. Rook's textbook of dermatology. 10th ed. Hoboken, NJ: John Wiley & Sons, Ltd; 2024.
2. Barthelmann S, Butsch F, Lang BM, et al. Seborrheic keratosis. J Dtsch Dermatol Ges. 2023 Mar;21(3):265-77.