Thank you for writing.
While we cannot tell you exactly what is going on, you may have a condition called Melasma.
Melasma is a skin pigmentation condition that can affect any woman.
It is unclear exactly what causes melasma but it appears as darkened brown, tan or blue/grey patches and spots usually around the nose, cheeks, forehead, upper lip (where you are experiencing) and chin.
There are three forms of melasma:
Epidermal - only occurs in the top layer of the skin which is treatable.
Dermal - develops in the deeper layers of the skin and is not treatable.
Mixed - a combination of both types so is partially treatable.
Melasma most commonly occurs on the face in the center, the cheek area (malar) or jawline (mandibular), however it can also appear on other parts of the body such as the neck or forearms.
Additionally, while the cause of melasma is not known there are factors that increase the risk of developing it such as:
-- pregnancy (called chloasma or the “mask of pregnancy”)
-- use of oral contraceptives
-- hormone replacement
-- family history
-- sun exposure
-- stress which may increase the release of melanin
Melasma that appears during pregnancy may go away on its own a few months after delivery and not need treatment. However, oftentimes it persists and may last for many years, worsening in the summer and improving in the winter.
It is very important that any treatment of melasma be directed by a dermatologist.
Medications that are used to treat melasma include:
Hydroquine - most common
Tretinoin - Retin-A
For more difficult cases, a doctor may use glycolic acid chemical peels and microdermabrasion.
Side effects from using these medications may include skin irritation and permanent skin discoloration. This is why it is crucial to only work with an experienced dermatologist.
If melasma is thought to be due to hormonal influences such as birth control pills or hormone replacement then discontinuing use of these medications should also be explored.
Important basic actions to prevent the worsening or recurrence of melasma after it is treated is to use a broad spectrum (UVA and UVB) sunscreen daily and avoiding the sun whenever possible by wearing hats, sunglasses and protective clothing.
FYI, I had melasma during pregnancy and not all of it went away. I also had brown areas like you describe, from sun exposure playing tennis. I use prescription Retin-A (Refissa) and have fractional co2 laser skin resurfacing every 2-3 years (which in itself is a total game changer in skin care).