hello, im dr satya.
itchy rash around pubic area, thigh, and bikini area,
common causes of itch aroud this area is candidiasis
, fungal infection
or also called tenia, alleric dermatitis
, id reactions, parasitic infestations such as scabies, and some rare disorders.
before concluding that you have something serious i would suggest that you follow a good hygiene
and consult a dermatologist
for a better evaluation.