For the black marks you can try applying kojic cream for a month which will decrease the pigmentation on the marks. for the nose..... There can be multiple causes for facial hyperpigmentation. Sun tan, overweight, pigmentation disorders like acanthosis nigricans or melasma, lichen planus pigmentosus, rhiel's melasnosis, nutritional deficiency etc are some conditions. The batches of pigmentation need to be examined and assessed to know the cause. Treating it without knowing the underlying cause will offer incomplete and temporary relief; also it will keep rebounding. Get an online consult or meet a dermatologist directly for a proper evaluation of the condition. Hope this was helpful.