Signs of an aloe vera allergy include irritated, red, or inflamed skin, rash, or a burning sensation in the area of where the aloe vera was applied. In addition to allergic reactions, aloe vera can cause other symptoms that are not necessarily the result of an aloe vera allergy, but a side effect of ingesting it. Nausea, vomiting, and diarrhea can occur when aloe has been ingested, even in small amounts. When allergic reaction or gastrointestinal symptoms occur, a physician should be notified who can recommend treatment to reduce the effects.

An aloe vera allergy can be quite severe in certain people. This typically occurs when aloe vera is injected or taken orally, rather than used as a topical preparation on the skin. Signs of a severe aloe vera allergy include low blood sugar and an electrolyte imbalance. Low blood sugar can cause lightheadedness, dizziness, shaking, and sweating. Replenishing glucose stores with juice, candy, or table sugar can often bring up blood sugar levels and eliminate symptoms.

People who have allergies to onions, garlic, or tulips may have a propensity towards an aloe vera allergy. Certain people who use aloe topical preparations for prolonged periods of time may develop an aloe vera allergy that includes symptoms such as eczema and hives. As with many allergic skin reactions, treatment can include over-the-counter antihistamine medications. These medications, although effective in relieving inflammation and itching, can cause significant drowsiness, dizziness, and confusion. They should never be taken when driving is anticipated or when operating dangerous machinery.

Aloe juice is sometimes taken to alleviate the effects of constipation. People should discuss this method of treating constipation with their primary physicians who can warn them of side effects that can occur when aloe juice is consumed. Drinking aloe for constipation can actually increase symptoms of abdominal cramping and bloating. In addition, it can cause severe diarrhea, which if prolonged, can even lead to dehydration.

Although aloe vera is considered safe when it is added to commercial products such as lotions and gels, consuming it in its raw form may not be prudent. It is not considered harmful, however, to use a small amount of aloe gel that has been extracted from the plant to put on a burn or other minor skin irritation. Aloe gel should not be rubbed into large areas of the skin and it should never be applied to cuts or broken skin.