QUESTION: How often can scalp steroid injections be done? I have alopecia areata and receive injections into the areas of hair loss every 4-6 weeks. Can I get these injections more often? Is my current frequency considered normal or excessive?
Thanks for the question. Let's first review a few things about steroid injections and then circle back to your question.
Steroid injections are used to reduce inflammation and are useful in a variety of hair loss conditions including alopecia areata, lichen planopilaris, frontal fibrosing alopecia, discoid lupus, traction alopecia, central centrifugal cicatricial alopecia and Pseudopelade of Brocq as well as a few others too.
The typical dose injected ranges from 2.5 mg of steroid per mL (ie 2.5 mg triamcinolone acetonide for every 1 mL of saline used) to a maximum of 10 mg per mL. Lower concentrations reduce the chance for “atrophy” (indentations in the scalp) and so many physicians opt for lower concentrations.
Generally speaking, steroid injections are performed as close as every 4 weeks apart. There is no maximum spacing and some patients benefit from injections every 4-6 months and others come into clinic whenever their condition flares. Injections more often than every 4 weeks are not typical.
20 mg every 4 weeks
A limited number of studies suggest that keeping the total dose to no more than 20 mg every 4 weeks has quite a good safety profile. This means a physician can use 8 mL of steroid solution every 4 weeks if they decide to use the 2.5 mg per mL solution. If the physician decides to use a higher concentration such as 5 mg per mL, he or she only has 4 mL available to inject. If one uses 10 mg per mL (which some physicians do), one only has 2 mL.
Some studies have suggested that injecting greater volumes of steroid solution at low concentrations works better than injecting smaller volumes of steroid solution at high concentration. For many patients, I even chose 1.5 or 2 mg per mL solutions and see how it works. Use of a 1.5 mg per mL solutions allows 15 mL of fluid to inject in the scalp (that’s 5 syringes!) ... and this goes alot further than trying to figure out where to inject 2 mL of a 10 mg per mL solution. Clearly, if low concentrations aren’t working, one needs to use higher concentrations at the next visit.
In summary, steroid injections can be performed as close as 4 weeks apart but one is not obligated to continue them at this interval. Limiting the concentration, total dose and frequency of injections helps to reduce side effects. In addition to “atrophy” discussed above, side effects can rarely include fatigue, irregular menstrual cycles in women, blood sugar changes and mood changes. These are not common. Longer term side effects to monitor include osteopenia, cataracts, weight gain and changes in blood pressure. These are quite rare with proper dosing and monitoring.
Chu TW, et al. Benefit of different concentrations of intralesional triamcinolone acetonide in alopecia areata: An intrasubject pilot study. Randomized controlled trial. J Am Acad Dermatol. 2015.