The U.S. Food and Drug Administration warned consumers Wednesday about mistakenly swallowing a Benadryl itch-relief gel rather than applying it to the skin.

The agency said it has received more than 100 reports of consumers swallowing Benadryl Extra Strength Itch Stopping Gel, an over-the-counter product sold by Johnson & Johnson. Benadryl is also sold in forms that are meant to be swallowed. Of those reports, seven were considered serious and required treatment in an emergency room or hospital.

Benadryl and similar generic products contain the active ingredient diphenhydramine. People swallowing a product meant for use on the skin can ingest a dangerous amount of diphenhydramine, which can cause hallucinations, loss of consciousness and confusion.

Earlier this year, Johnson & Johnson redesigned the bottle to state that it was meant for skin use only and it attached a yellow sticker to bottle cap that states "for skin use" only.

The agency said it is advising consumers and pharmacies to store products for the skin separately from products that should be swallowed. The FDA noted that many pharmacies and grocery stores sell diphenhydramine topical gels that look very similar in packaging to Benadryl Extra Strength Itch Stopping Gel.

Benadryl itch gel has been on the market for more than 15 years, according to a J & J spokeswoman. However, the company received a "small" number of reports from consumers who had ingested the product.

The FDA said between 2001 and 2009, a total of 121 cases of mistaken ingestion of Benadryl Extra Strength Itch Stopping Gel were reported to the manufacturer.