Love DermNet?

Subscribe to our monthly newsletter.

Reticular erythematous mucinosis pathology

Author: Assoc Prof Patrick Emanuel, Dermatopathologist, Auckland, New Zealand, 2014.

Reticular Erythematous Mucinosis or REM is a rare dermatosis characterised by papules and plaques on the upper trunk which often coalesce into a reticulated pattern. Some authors consider this entity a form of cutaneous lupus erythematosus.

Histology of reticular erythematous mucinosis

In REM, sections show a superficial and deep perivascular and periadnexal mononuclear infiltrate (figure 1). The epidermis is uninvolved. The presence of copious mucin between collagen fibres of the dermis is characteristic of the disorder (figures 2, 3).

Special studies for reticular erythematous mucinosis

The mucin may be difficult to appreciate on routine H-E sections. Special stains for mucin (such as colloidal iron or hyaluronic acid) can be helpful to confirm the presence of dermal mucin.

Differential diagnosis of reticular erythematous mucinosis

Scleredema – This entity also shows mucin deposition but typically lacks an associated inflammatory infiltrate.

Lupus – Tumid lupus can look identical to REM. The clinical presentation can help distinguish these entities. Some authorities consider REM a form of lupus.

Related information

Make a donation

Donate Today

Help us to update and maintain DermNet New Zealand

Submit your images

We are expanding our image library

Contact us

Skin lesion photography

Watch Dr Amanda Oakley presenting "Skin lesion photography" at The Australasian Skin Cancer Congress.

Subscribe to our mailing list

* indicates required
DermNet NZ Newsletter