An unusual pattern of alopecia areata.

Sir,

Alopecia areata (AA) - the most common T-cell-mediated autoimmune loss of hair of all colors associated with collapse of hair follicle immune privilege - has a 2% lifetime risk,[1] and a peak incidence between the second and fourth decades of life.[2] The typical AA patient most often presents with one or a few, nonscarred, round or oval, sharply demarcated alopecic patches involving - in decreasing order of frequency - scalp, beard, eyebrows and eyelashes. Its variants involving scalp entirely (alopecia totalis) or as patterned (sisaipho and ophiasis) are unusual and involving all hair bearing sites (universal AA), uncommon.[3] We present a case of “extensive” AA that retained hair only on vertex of scalp, confounding us regarding its precise type.

A 29-year-old male presented with history of loss of hair 6 months ago commencing as a small patch over the occiput and gradually extending not only over the entire circumference of scalp (except the vertex) but also relentlessly progressing over all other hair bearing areas. This hair loss was unassociated with itching/burning or any other systemic complaints. Dermatological examination revealed diffuse non-scarring loss of hair from the entire body except the vertex of the scalp [Figures 1 and 2], hair pull test on which was negative. Nails revealed fine pitting. General physical - and systemic examinations were normal. Administration of four, monthly dexamethasone cyclophosphamide (DCP) pulses revealed no hair regrowth. Unfortunately, the patient got lost to follow-up.

Figure 1

Non-cicatricial alopecia involving scalp, eyebrows, eyelashes, beard, moustache, nose, ears and upper chest

Figure 2

Non-cicatricial alopecia involving the occiput and suprauricular areas

Alopecia areata can be classified into many subtypes; patchy AA (75%) being the most common. A subset of patients (10-20%) suffer from alopecia totalis losing all scalp hair; others, develop universal AA losing hair from all sites including eyebrows, eyelashes, nose, and ears. A special band-like pattern of AA, usually recalcitrant to treatment, winding along the occipital hairline extending toward the temples has been called ophiasis; in its inverse, sisaipho, type hair are lost centrally and spared at the margins frontoparietooccipitally mimicking androgenetic alopecia. In diffuse AA, more common in women aged over 20, diffuse sudden hair loss-evolving totally in less than 3 months and regrowing totally in 5-9 months - extends over the whole scalp but usually does not affect all sites; hair pull test is positive. Rectangular occipital AA - paraneoplastic association with diffuse lymphoma, alveolar soft tissue sarcoma, etc. - affects occipital region and sometimes, supraauricular area.[4]

Complete loss of scalp hair is common to total AA as well as universal AA. Our patient had a complete loss of body hair with retention of just the hair on vertex of his scalp, thereby confounding us as regards the precise type of alopecia wherein extension of his near universal alopecia, somehow, did not involve vertex of the scalp for at least 8 months, 4 months before and 4 months after DCP therapy. We failed, despite a diligent search of the literature, to find a similar case and reason, if any, for this prolonged retention of hair only on the vertex of scalp despite progressive alopecia at all other sites. Hence we continue to wonder and are at a loss whether this interesting presentation of AA was extensive ophiasis along with alopecia of other hair bearing sites or a unique pattern of AA!