Failure to detect clonality in eosinophilic pustular folliculitis with follicular mucinosis.

Eosinophilic pustular folliculitis is characterized by an eosinophil-rich inflammatory follicular and perifollicular infiltrate primarily centred at the level of the follicular isthmus and sebaceous duct. Follicular mucinosis has been observed in lesions of eosinophilic pustular folliculitis. Clinical and histological features of eosinophilic pustular folliculitis with follicular mucinosis and alopecia mucinosa are very similar. Alopecia mucinosa may be a clonal T-cell dermatosis. A monoclonal re-arrangement of the T-cell receptor gene was detected in about half of the cases in alopecia mucinosa. To investigate T-cell clonality in a series of eosinophilic pustular folliculitis with follicular mucinosis, we performed heteroduplex analysis of re-arranged T-cell receptor gamma gene in seven cases of eosinophilic pustular folliculitis with follicular mucinosis. All cases were negative for heteroduplex-PCR analysis. The failure to demonstrate clonality may be consistent with a reactive nature of eosinophilic pustular folliculitis with follicular mucinosis.