Keratin, a protein present in skin, hair, and nails, is vital for both humans and animals. According to an expert, the accumulation of keratin can occasionally result in the development of horns in some individuals.

Dan Baumgardt, a senior lecturer at the University of Bristol, explained that cutaneous horns, also known as cornu cutaneum, are dense masses of keratin that protrude from the skin, resembling the horns of certain animals like goats, sheep, or cows.

These horns can exhibit various colors such as yellow, brown, or grey, depending on the pigmentation and dead cells trapped within the keratin buildup. Baumgardt mentioned that cutaneous horns often originate from benign skin lesions like seborrheic keratoses or warts, including those caused by the human papillomavirus (HPV).

Approximately 16-20% of cutaneous horns are malignant and can stem from skin cancers like squamous cell carcinoma, which may spread to deeper tissues if untreated. Some horns arise from premalignant conditions like actinic keratosis, which can progress to cancerous forms.

Usually affecting older adults with fair skin, horns tend to appear on sun-exposed areas like the face or head due to the influence of ultraviolet (UV) light. While most horns are harmless, some may be linked to cancer, prompting individuals to seek medical attention for proper evaluation and treatment, often involving surgical removal.

Notable cases of extreme horn growth, such as the elderly woman from China with a 10-centimeter horn on her forehead, have garnered public attention. Madame Dimanche, a French woman from the 19th century, had a horn that extended nearly 25cm before its removal, with a wax cast preserved at the Mütter Museum in Philadelphia.

Baumgardt emphasized the importance of consulting a healthcare provider upon noticing any horn-like growth for timely evaluation and appropriate management.