Another clue to infestation is odor. Like many species of bugs, bed bugs release odors called alarm pheromones. When a group of bed bugs gets disturbed, you may get a whiff of that odor, which is similar to the odor stink bugs give off. At higher concentrations the odor is unpleasant. Some people say at low concentrations it's a pleasant smell—like coriander. In fact, older literature refers to the bed bug as the coriander bug. I've tried to smell the coriander scent in bed bug alarm pheromones and have not been able to make the connection, however.
Cutaneous reactions to bedbug bites can vary widely and are easily confused with other conditions (Table 1).15–19 A typical lesion is a 2- to 20-mm, pruritic, erythematous maculopapule with a central hemorrhagic crust or vesicle.5,8 Macules, papules, wheals (Figure 3), vesicles, bullae, and nodules have all been reported,20 as have asymptomatic lesions with a barely visible punctum as the only evidence of a bite.8 Bites vary in number and are preferentially distributed in unclothed areas (e.g., face, neck, extremities). Unlike many other arthropod and insect bites, bedbug bites are rarely located in the popliteal fossae or axillae.21 Lesions can be noticeable immediately when waking up or several days later, with the reaction often progressing from delayed to immediate with subsequent exposures22–26 (Table 2). The classic bedbug rash is referred to as “breakfast, lunch, and dinner” because it commonly presents as several bites in a row or cluster 20 (Figure 4).
A bedbug is a small, blood-sucking parasite that feeds on mammals and birds. Bedbugs belong to the insect family Cimicidae. Although there are several different species, the most common species associated with human bedbug infestations are Cimex lectularius and Cimex hemipterus. Bedbugs are considered a public health pest. There has been a recent resurgence in bedbug infestations worldwide, particularly in developed countries, including the United States.
Blood spots found on one’s sheets, bites and the presence of bed bug feces and cast skins are some of the indications of a bed bug infestation. Bites are commonly found on the parts of the body that are more likely to be exposed to bed bugs during sleep – the hands, neck, face, shoulders, legs and arms. While not always the case, bed bug bites are often grouped together in a small area and at times may occur in a line or a zigzag pattern. Bites normally look like small, flat or raised areas that may become inflamed, itchy, red or blistered. Bed bug bite reactions don’t always appear immediately after you’re bitten and may take a few days to begin causing symptoms. However, not everyone reacts to bed bug bites in the same manner.