What Kind of Health Conditions Could Cause Rapid Volume Loss in the Face?

Say the person in there 20s and the volume loss occurs over less than 2 months. No weightloss, HIV negative, and otherwise feel healthy. The change is so significant that people think the person has lost a substantial amount of weight ( more that 20lb) or is sick. The loss is bilateral and symmetrical all over. It's like an entire layer of subcutaneous tissue vanished. For a male, could sudden low testosterone ( but normal estrogen) cause this? If so, doesn't Higher T cause there to be less fat?