3. Epidermodysplasia verruciformis, Tree Man Syndrome
What appears to be tree bark growing out of someone’s skin may actually be Epidermodysplasia verruciformis. Of course, it isn’t bark. These growths are actually warts that can be exacerbated by exposure to sunlight. While these warts may be benign early in life, they can become malignant later in life.
The warts are caused by a rare mutation of the EVER1/EVER2 genes. Though the function of the genes isn’t really well-understood, the mutations cause the skin to be extremely susceptible to human papillomaviruses 5 and 8, which typically don’t cause disease. While there are some treatment options available to mitigate the symptoms, there is no cure.
4. Alien Hand Syndrome
The phrase, “the right hand doesn’t know what the left is doing” is actually literally true for some people. The condition involves a rogue hand that acts independently, grasping objects or moving in a way contrary to what the individual wishes to do.
Sometimes, a rare side effect to brain injuries or surgical severing of the corpus callosum is the inability to control the actions of one hand. There is no cure for this condition, though the symptoms can be managed by making sure the hand is actively engaged in activity.