**Core Concept**
The patient's presentation is suggestive of a chronic skin condition characterized by hypopigmented lesions, typically around follicles, and fine scaling. This condition is often associated with an underlying immune response and may have a relapsing course.

**Why the Correct Answer is Right**
The description provided is consistent with pityriasis versicolor (PV), a common skin infection caused by Malassezia yeast. The lesions are often seen on the upper chest and back, and the fine scaling is a characteristic feature. The coalescence of lesions to form large sheets and the recurrence of similar lesions in the past also support this diagnosis. The surface of the macules showing fine scaling is due to the presence of yeast on the skin surface.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option might be tempting due to the presence of hypopigmented lesions, but it is not the best choice for this scenario. Pityriasis alba is typically seen in children and does not have the characteristic fine scaling or follicular distribution.

**Option B:**
This option is not relevant to the clinical presentation. Tinea versicolor is another name for pityriasis versicolor, but it's not the best choice as it does not provide a clear investigation option.

**Option C:**
This option might be considered due to the presence of hypopigmented lesions, but it's not the best choice. Pityriasis lichenoides is a rare skin condition that typically presents with small, lichenoid papules, not hypopigmented macules.

**Option D:**
This option is not the best choice as it does not directly relate to the investigation of the skin condition. Skin scrapings or potassium hydroxide (KOH) examination would be more relevant.

**Clinical Pearl / High-Yield Fact**
One key feature of pityriasis versicolor is its characteristic fine scaling, which can be a helpful clue in diagnosis. It's essential to perform a skin scraping or KOH examination to confirm the presence of Malassezia yeast.

**Correct Answer:** D. Skin scrapings or KOH examination