Conjunctival pigmentation associated with tetracycline medication.

A 26-year-old man had been treated for acne vulgaris with tetracycline and minocycline orally for 12 years. He developed dark brown to black pigmentary deposits in the palpebral conjunctiva bilaterally. These deposits resembled those seen in epinephrine pigmentation of the conjunctiva. Histologically the pigmented deposits were concretions in conjunctival cysts. Although they contained calcium, the concretions displayed the characteristic yellow autofluorescence of tetracycline under ultraviolet light. Presumably, tetracycline had formed extracellular chelation complexes with calcium, thus accounting for the pigmentation of the conjunctiva.