Obagi Medical Products Inc. said Thursday that its fourth-quarter earning fell more than 50 percent on slower sales of its skin care products.

The Long Beach company, whose products are sold in doctor’s offices, also set lower expectations for its first quarter than Wall Street has.

Obagi reported net income of $2.2 million (10 cents per share), compared with $4.5 million (20 cents) a year ago. Sales fell nearly 7 percent to $25.4 million. Analysts surveyed by Thomson Reuters on average expected net income of 13 cents per share on revenue of $26.2 million.

Chief Executive Steve Carlson said things could have been worse.

“Revenues were down just 2 percent from the third quarter, while more expensive discretionary surgical and cosmetic procedures reported more dramatic declines of up to 30 to 50 percent sequentially,” Carlson said in a statement. “In the current economic climate this indicates to us that while more costly procedures can be postponed or foregone, Obagi’s products continue to have an important place in our customers’ daily lives.”

For the full 2008 year, the company’s earnings fell 17 percent to $12.6 million (56 cents) compared with 2007. Sales rose 2 percent to more than $104 million

The company expects first quarter net income of between 8 cents and 10 cents per share on revenue of between $22 million and $24 million. Analysts on average are expecting profit of 12 cents on revenue of $23.8 million.

Shares of Obagi fell 47 cents, or 11 percent, to $4 in morning trading on the Nasdaq.