Corticosteroid injections are a common medical procedure used to reduce inflammation in specific areas of the body, such as joints, tendons, cysts, or scars. These localized treatments offer significant relief for various orthopedic and dermatologic conditions. A frequent concern for patients is the potential for visible changes in the appearance of the skin overlying the treatment site. This article explores whether steroid injections cause skin discoloration and the mechanisms behind this side effect.
The Primary Skin Reaction: Hypopigmentation
Steroid injections can cause noticeable changes in skin color, most frequently hypopigmentation. This reaction appears as a localized patch of skin significantly lighter than the surrounding area. The hypopigmented area is typically a poorly circumscribed patch that develops around the injection site within one to four months following the procedure.
This side effect, occurring in an estimated 1.3% to 4% of patients, results from the medication’s local effect on pigment-producing cells. The contrast created by the lighter patch is often more prominent in individuals with naturally darker skin tones. Less commonly, temporary darkening (hyperpigmentation) may be observed, but this usually resolves quickly.
How Steroids Affect Skin Pigment and Tissue
The biological mechanisms causing discoloration involve the corticosteroid’s direct action on skin cells and surrounding tissue. The primary cause of hypopigmentation is the medication’s effect on melanocytes, the cells responsible for producing melanin. Corticosteroids suppress the function of these cells, leading to a temporary reduction in melanin production. Evidence suggests melanocytes remain present but are less active, rather than being permanently destroyed.
This pigment change is often compounded by localized tissue atrophy. Corticosteroids inhibit fibroblasts, which produce collagen and elastin, and alter fat metabolism. This leads to the breakdown of subcutaneous fat beneath the injection site. The resulting loss of underlying tissue creates a visible indentation or depression, which can make the hypopigmentation appear more severe.
Duration and Management of Skin Discoloration
For most patients, the skin discoloration caused by a steroid injection is not permanent. Hypopigmentation typically resolves spontaneously as the steroid compound is metabolized and cleared from the localized tissue. Repigmentation usually occurs over several months, with many cases resolving within six to twelve months. In some instances, however, the discoloration can persist for up to 18 months or longer.
The associated soft tissue atrophy may also gradually improve as the body naturally restores lost subcutaneous fat and collagen. Protecting the affected area from sun exposure is a practical management step, as tanning the surrounding skin increases the visual difference with the lighter patch. Patients should consult their physician if the discoloration or atrophy is severe, persists beyond a year, or if they have concerns about the appearance. Specialized treatments like intralesional saline or fat grafting have been used for persistent cases.