Macular hypopigmentation, hair loss and follicular spongiosis: A distinct clinicopathological entity.

BACKGROUND: Hypopigmented macules are seen in a variety of disorders and the diagnosis rests on clinicopathological correlation. However, some cases are difficult to classify and pose a diagnostic challenge.

AIM: To describe the clinical and histopathological features of patients with hypopigmented macules and follicular spongiosis on histopathology.

MATERIALS AND METHODS: We undertook a retrospective analysis of clinical and histopathological findings in 12 patients who presented with clinically nondiagnostic hypopigmented macules and showed follicular spongiosis on skin biopsy, at All India Institute of Medical Sciences, New Delhi, India between January 2015 and October 2016. The findings were compared with 12 patients with "unclassified" hypopigmented macules, who did not show follicular spongiosis on skin biopsy.

RESULTS: A total of 12 patients with hypopigmented macules showed spongiosis affecting the follicular epithelium on histopathology. There were eight men and four women, most in their second decade (mean age 19.1 ± 8.05 years), presenting with hypopigmented macules most commonly on the upper limbs, for a mean duration of 6.33 ± 5.10 months. Clinically evident lesional hair loss was seen in all patients, and follicular prominences in seven (58%) patients. Histological features suggestive of other diagnosis, namely leprosy, mycosis fungoides or sarcoidosis were not seen in any biopsy. Alcian blue stain revealed an minimal amount of mucin in one biopsy. Clinically apparent hair loss and follicular prominences were found to be statistically significantly associated with histological evidence of follicular spongiosis (P < 0.001 and 0.003, respectively).

LIMITATIONS: Our study is limited by its retrospective design and small sample size.

CONCLUSIONS: Patients with hypopigmented macules and follicular spongiosis on histopathology may represent a distinct clinicopathological entity that is associated with lesional hair loss and follicular prominences. It is probably a variant of an endogenous dermatitis similar to pityriasis alba.