Darier's sign and osteoporosis

Melissa, a 61-year-old woman, was referred for evaluation and management of osteoporosis. She was “petite,” with a weight of 115 lb and heigh of 64 inches. She had a bone density study performed at that time (data not available) and was started on alendronate. After 2 years, the therapy was discontinued.

Shortly before this clinic visit, she had a follow up DXA study, which demonstrated a spine T-score of –4.6 and a proximal femur T-score of –5.1 — both values that you and I see infrequently.

A detailed medical history provided no immediate clues to the etiology of this very low bone mass, and physical examination was also not helpful.

On a whim, I tried Darier’s sign on her back and in less than a minute the “wheal -and-flare” reaction was very apparent. I then demonstrated the same response on her forearm so she would understand what I was describing.

The following paragraph was taken directly from “UpToDate”:

Darier's sign — Darier's sign is defined as the development of urticaria and erythema (within about five minutes) of rubbing, scratching, or stroking skin or skin lesions that are heavily infiltrated with mast cells [40]. This finding arises when physical irritation triggers the localized release of mast cell mediators. Darier's sign is present in various forms of mastocytosis involving the skin, including UP, diffuse cutaneous mastocytosis, and mastocytomas (although the latter should not be purposefully rubbed, as this can precipitate symptoms).

Soter NA. Mastocytosis and the skin. Hematol Oncol Clin North Am 2000; 14:537.

I do not see this condition very often and have elected to refer her to my dermatology colleagues for more complete evaluation and recommendations before beginning osteoporosis therapy. It would not surprise me if they recommend specific non-skeletal therapy even in the presence of such low bone mineral density.

I would welcome a response from those of you who have more clinical experience with this clinical situation.