Would sclerotherapy look like this? (Photo)

I recommend following up with your Doctor for after care recommendations. This may be due to extravasation of the solution outside the vein being treated.  See an expert. Best, Dr. Emer

Thank you for your question in regards to sclerotherapy. From your photo it appears that you could be developing skin necrosis. Follow up with your provider to discuss proper post care instructions. I hope this helps.

The area that you show in the picture looks like the beginning of skin necrosis from sclerosant liquid leaking out of the vein during vein injections.  This can form an ulcer.  I would recommend following up with your physician

The posted picture is suggestive of early skin necrosis.  You need to return to your treating physician for an evaluation.  Local care for now with warm compresses and a topical antibacterial ointment may give some temporary relief.

Consider a follow up visit with your physician to help you manage your care post procedure and/ or possible complications of procedure. 
Best, 

An in person follow up is necessary. Some scerlosants, as in this ones, cause tissue necrosis when they infiltrate the skin. This is most likely with hypertonic saline and not seen with Polidochanol or STS.I recommend the use of Scar Serum and Dark Scar Corrector to prevent hyperpigmentation. Both products are on the link below. I do a large number of sclerotherapy procedures and I recommend this regimen to reduce post inflammatory hyerpigmentation in the area. See link below for these products. There are also some creams that we recommend after sclerotherapy to reduce hyeprpigmentation: Sclerovase and Scleroquin plus.