Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders.

Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation.

Minocycline-Induced Hyperpigmentation of Nails.

Minocycline is an antibiotic used for several dermatologic conditions, including rosacea. The development of skin, scleral, and nail hyperpigmentation may occur with long-term use of minocycline, and this is associated with no adverse effect on function. We present a case of a 66-year-old male who developed blue-gray hyperpigmentation of his nail beds after treating rosacea with systemic minocycline for over 20 years. The remainder of the physical exam was unremarkable for hyperpigmentation elsewhere. The patient was informed that this was likely an adverse effect of his chronic minocycline use. He insisted upon the continuation of minocycline, so he was counseled on the adverse effects of the medication and scheduled for follow-up.

A case of hyperpigmentation and acanthosis nigricans by testosterone injections.

Drug-related skin disorders may occur in many different ways. Despite pigmentary changes being less important for morbidity, these changes precipitate depressed mood and reduce self-confidence. Testosterone is a steroid hormone from the androgen group and primarily used for the treatment of hypogonadism in males. Testosterone replacement can cause skin problems like acne, hair loss, redness, pain, or infection at the injection site. The study was conducted on a 49-year-old man with adult onset idiopathic hypogonadotropic hypogonadism, which is an acquired form of isolated gonadotropin-releasing hormone deficiency. He was presented with lack of energy and decreased sexual function 10 years ago and was given an oil-based injectable blend of four esterized testosterone compounds as hormone replacement treatment in a urology polyclinic. He was referred to our polyclinic by endocrinologist because of progressive hyperpigmentation marked on his face and oral mucosa. In the present study, we report the first testosterone therapy-related facial and oral mucosal hyperpigmentation and acanthosis nigricans in the same patient.