Morphea represents a thickening of collagen bundles in the skin. Although morphea can affect the shoulder and trunk, as Becker melanosis does, lesions of morphea feel firm to the touch and are not associated with hypertrichosis.
Localized post-inflammatory hyperpigmentation occurs following a traumatic event, such as a burn, or a prior dermatosis, such as zoster. Careful history-taking can uncover an antecedent inflammatory condition. Post-inflammatory pigment changes do not typically result in hypertrichosis.
Café-au-lait macules can manifest as isolated areas of discoloration. These macules can be an important indicator of neurofibromatosis, a genetic disorder in which tumors grow in the nervous system. Melanocytic hamartomas of the iris (Lisch nodules), axillary freckling (Crowe’s sign), or multiple cutaneous neurofibromas serve as additional clues to neurofibromatosis. In ambiguous cases, a skin biopsy can help differentiate a café au lait macule from Becker melanosis.
To treat or not to treat?
No treatment other than reassurance is needed in most cases of Becker melanosis, as it is a benign condition. Protecting the area from sunlight can minimize darkening and contrast with the surrounding skin. Electrolysis and laser therapy can be used to treat the associated hypertrichosis; laser therapy can also reduce the hyperpigmentation. Nonablative fractional resurfacing accompanied by laser hair removal is also reported to be of value.6
Our patient was satisfied with reassurance of the benign nature of the condition and did not elect treatment.
CORRESPONDENCE
Matthew F. Helm, MD, 500 University Drive, Suite 4300, Department of Dermatology, HU14, UPC II, Hershey, PA 17033-2360; Mhelm2@pennstatehealth.psu.edu