Shares of Dusa Pharmaceuticals Inc. surged Thursday after the company said sales of its Levulan Kerastick skin treatment grew strongly for the second consecutive quarter.

Dusa makes treatments using light to treat acne and other skin disorders. One, Levulan Kerastick, is a light-sensitive drug that is applied to actinic keratoses, or precancerous growths, on the face and scalp. The drug makes the growths sensitive to light. It is then exposed to a blue light that breaks up the patches.

The company said Kerastick sales volumes rose 22 percent in the first quarter, with sales reaching 75,213 units. That and higher prices pushed revenue 35 percent higher to $10.5 million.

The stock advanced $1.17, or 25.8 percent, to $5.70 in afternoon trading.

Dusa reported a loss of $605,000 in the first quarter, compared with $425,000 a year ago. Its per-share loss was unchanged 2 cents. Total revenue rose 27 percent, to $11.1 million from $8.7 million.

The company posted a larger loss because the value of its share price has increased. As a result of its higher share price, the company recorded a charge of $2.2 million on the value of warrants it issued in 2007 to raise cash. In the first quarter of 2010, it reported a similar loss of $199,000.

Dusa's share price grew 33.9 percent between the end of the first quarter of 2010 and the start of the first quarter of 2011, rising to $2.45 from $1.83. The shares more than doubled in value during the most recent quarter and closed the period at $5.20.