Glochid

: "glochidium") are hair-like spines or short prickles, generally barbed, found on the areoles of cacti in the sub-family Opuntioideae.

Cactus glochids easily detach from the plant and lodge in the skin, causing irritation upon contact.

Distraction or excitement might cause the victim to overlook brushing past a cactus and picking up a few hundred barely visible glochids.

Shanon reported that brushing his axillary skin with sabra fruit resulted in no symptoms for a half-hour, followed by 1+1⁄2 hours of "stabbing feelings".

[2] Depending on the exposure, widespread areas may be involved, even extending to hard palate, tongue, conjunctiva and cornea.

Within 24 to 72 hours there is the appearance of 2- to 5-mm, asymptomatic, domed, glistening papules, sometimes erythematous, with a central pin-point-sized black dot at the site of the injury.

[1] In some instances, diagnosis can be made easily by passing the fingers over the affected area and by feeling the embedded glochidia.

[8] Typical areas of involvement of this irritant dermatitis include fingers, wrists, genitals, thorax, and buttocks.

Yanking out the bristles may result in leaving one or more 20–30 micrometre sized barbs in the skin, later to be manifest by granuloma formation.

The method using a thin layer of household glue covered with gauze, allowed to dry (about 30 minutes) and then peeled off resulted in removal of 63% of the spines.