DISCUSSION
Only one English study has described multiple papular lesions on an
erythematous background as the dermoscopic finding of follicular
mucinosis 3. In the present case, the
histopathological finding of mucin deposits in the follicular
infundibulum and isthmus appear to correspond to the dermoscopic
findings of brownish yellow dots in the follicular ostium. Also, the
histopathological findings of dilated capillary vessels appear to
correspond to the dermoscopic findings of red dots in the
interfollicular area.
Yellow dots are a trichoscopic finding that corresponds to a dilated
follicular infundibulum filled with keratotic material and/or sebum.
They are observed as rounded or polycyclic structures with colors
ranging from pinkish yellow to brownish yellow 4. This
finding has been subsequently detected in various diseases, such as
alopecia areata, chronic cutaneous lupus erythematosus, androgenetic
alopecia, dissecting cellulitis, and, less frequently, trichotillomania5. Therefore, brownish yellow dots in the present case
are not specific to follicular mucinosis.
Red dots are a dermoscopic finding that corresponds to dilated vessels
aligned perpendicular to the skin surface 6. This
finding has been subsequently detected in melanocytic lesions such as
melanoma and melanocytic nevus as well as inflammatory diseases such as
psoriasis 6. Therefore, red dots in the present case
are not specific to follicular mucinosis. In that context, the
combination of both brownish yellow dots and red dots appears to be
non-specific. However, this case report suggests that dermatologists
should consider the possibility of follicular mucinosis when such
dermoscopic findings are obtained.