For what it is worth (for me it was worth much) here is a pdf file that some of you may be able to read and find helpful. For me the help came in this paragraph ”
The high proportion of cases reported among these populations suggests a genetic susceptibility for LP. This idea is further supported by cases of familial LP, reported in 1 to 4.3% of childhood LP series (Kanwar and De, 2010; Nanda et al., 2001). However, familial cases have not been reported in all series, and specific antigens have yet to be determined. Pathogenicity of LP lesions involves the autoimmune-mediated lysis of basal keratinocytes by CD8+ lymphocytes, though definitive etiological triggers are still unknown. Case reports in both adults and children have shown an association between LP and the following: chronic liver diseases such as chronic active hepatitis (particularly hepatitis C) and primary biliary cirrhosis; complication of hepatitis B vaccination; viral and bacterial antigens; trauma (via the Koebner phenomenon); metal ions; medications; and a variety of autoimmune diseases such as autoimmune thyroiditis, myasthenia gravis, alopecia areata, vitiligo, thymoma, and autoimmune polyendocrinopathy (Luis-Montoya et al., 2005; Pandhi et al., 2014).  IN PARTICULAR  linking METAL ions to this disease is what I am thinking happened in my case, the metal ions as chromatic agenets in the thinset mortar and the grout that I used on my basement floor. Chromium and cobalt, and hopefully no cadmium, but plenty of other metal elements, and also including the silica, known to cause respiratory disease.

This particular paper suggests that corticosteroids are beneficial, but many sites and publications do not give steroids much credit for shortening the duration of the disease, which can be years. I for one wasnt helped by topical steroid cream (betamethasone was the only one prescribed for me, outside of a very outdated half used tiny sample tube of topicort none others were used).

Next chapter begins a fun 11 or 12 years making ceramic tile collages, montages, outdoor pots (big big ones) and laying 35 thousand tesserae on my basement floor.  Little by little over that span i began to notice a dry cough.  Not that bad, but bothersome.