I have black layer on my things and some itch on there &also on remain parts of lower body it is from 1 month.

Question

This can be taenia nigra, a type of fungal infection. 
. Let us consider the treatment of a fungal infection in the groin region i. e. around genitals.  
 First thing what you need to do is, keep the area clean. Then see to it that the region is always dry because Wet and moist environment provides nice place for fungus to breed.
Change the underwear daily. 
Old underwears to be thrown, please buy new ones.  
 Stop smoking, tobbacco chewing, alcohol etc. habbits if present. 
 Maintain good diet without sweet for a few days in non diabetics, diabetics need blood sugar level control.
Medicines can be prescribed if not getting cured by these simple measures.

Regards.

Parvez F. A. · Accepted Answer

This can be taenia nigra, a type of fungal infection. 
. Let us consider the treatment of a fungal infection in the groin region i. e. around genitals.  
 First thing what you need to do is, keep the area clean. Then see to it that the region is always dry because Wet and moist environment provides nice place for fungus to breed.
Change the underwear daily. 
Old underwears to be thrown, please buy new ones.  
 Stop smoking, tobbacco chewing, alcohol etc. habbits if present. 
 Maintain good diet without sweet for a few days in non diabetics, diabetics need blood sugar level control.
Medicines can be prescribed if not getting cured by these simple measures.

Regards.