As with any medication, there are possible side effects or risks involved. Common risks from steroid injections include pain at the injection site, bruising due to broken blood vessels, skin discolouration and aggravation of inflammation. Rarer risks include allergic reactions, infection, tendon rupture and serious injury to bones called necrosis. Long term side effects (depending on frequency and dose) include thinning of skin, easy bruising, weight gain, puffiness in the face, higher blood pressure, cataract formation, and osteoporosis (reduced bone density). Steroid injections may be given every 3-4 months but frequent injections may lead to tissue weakening at the injection site and is not recommended. Side effects do not happen in everyone and vary from person to person.
Although side effects are unlikely to occur with one injection, they can occur, and this should be taken into consideration when opting for the treatment. You may experience weakening of the muscles and ligaments surrounding the injection site leading to pain and instability. The fat pad in the ball of the foot may also atrophy , or shrink, causing a small indentation in the tissue and even greater long term pain. In addition, the pigment of the skin can lighten, but this is rare and usually happens only in darker skinned patients. For this reason, it is important to find a doctor who is skilled in treating Morton’s neuroma with corticosteroid injections. The use of ultrasound guidance also increases the accuracy of the injection and decreases the likelihood of complications. If the needle is misplaced, side effects are more likely to occur.