Reticular Erythematous Mucinosis or Lupus Erythematosus Tumidus : A Diagnostic Dilemma!

Dr. Priyanka Thakur

Junior Resident

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. Reena Sharma

Assistant professor

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. K . S. Mehta

Professor and Head

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. P. S. Chauhan

Associate Professor

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. Anju Lath

Assistant Professor

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Abstract

Reticular erythematous mucinosis (REM) is an idiopathic cutaneous mucinosis characterized by erythematous macules, papules and plaques which amalgamate to form specific reticular pattern. It typically involves the midline of the chest or back. Lupus erythematosus tumidus (LET) is an uncommon and highly photosensitive form of chronic

Dr. Anuj Sharma

Assistant Professor

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. Sujaya Manvi

Senior Resident

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. Amisha

Junior Resident

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh

Dr. Rohit Negi

Junior Resident

Department of DVL, Dr Rajendra Prasad Government Medical College, Tanda, Kangra, Himachal Pradesh cutaneous lupus erythematosus (CCLE). It has been classically defined as annular erythematous, succulent, plaques involving face and trunk. Although REM and LET share similarities but distribution of lesions together with histopathological features may aid in distinction between these two entities.

Introduction

Reticular erythematous mucinosis is a disorder of dermal mucin accumulation affecting women in third and fourth decade of life although men can be affected.(1) Lupus erythematosus tumidus occur in photodistributed pattern in the form of urticarial plaques or papules without scaling, dyspigmentation and scarring.

(2) The distinction between REM and LET has been a subject of debate. REM needs to be distinguished from LET, since REM does not involve internal organ and procures good prognosis.

Case report

A 47 year- male presented with progressive asymptomatic, multiple reddish flat to raised lesions over the central part of chest and forehead involving hairline and associated with lesional loss of hair for last four years. The lesions become prominent on exposure to sunlight. The patient denied history of prior drug intake. There was history of smoking tobacco for last 20 years. Family history was non contributory.

On clinical examination of frontal aspect of scalp revealed single well defined erythematous band like plaque measuring 9×4 cm with alopecia with atrophy. There was symmetrical involvement of chest in the form of well defined erythematous reticulated plaques of size ranging from 14×6 cm on the right side and 15× 5 cm on the left side with smooth surface and partial loss of hair. The aforementioned lesion blanched incompletely on pressure. The back, extremeties and mucosa were spared. The systemic involvement was non contributory. The possibilities of REM and LET were kept clinically. Routine lab investigations including complete blood count, serum biochemistery, urine analysis, thyroid function test, chest X-ray and abdominal ultrasonography were essentially normal. Antinuclear antibodies and direct immunofluroscence test was negative. A 4mm punch biopsy from lesional skin of chest showed flattened epidermis. There was superficial to mid perivascular and periadenexial inflammatory cell infiltrate predominantly of lymphocytes. Alcian blue staining showed homogenous deposition of mucin in the superficial dermis.

Diagnosis of REM syndrome was made on the basis of history, characteristic morphology and corroborating histolopathology. After clearance by an ophthalmologist, he was given tab hydroxychloroquine 200 mg twice daily, topical tacrolimus 0.1% once daily application at night, broad spectrum sunscreen and photoprotection was advised. Smoking cessation and effect of smoking on the disease thoroughly discussed with the patient. The patient showed remarkable improvement after 6-8 weeks and is under follow up.

Discussion

Amongst the diverse group of cutaneous mucinosis, REM is a rare form of primary cutaneous mucinosis which was first described by Steigleder in 1974.(3) It most often involve the midline of upper chest or back in middle aged women although men and children are not spared. Hallmark features are erythematous macules and indurated papules or plaque having reticular configuration. They lack surface changes or scaling. The typical site is midline of chest or back ergo known as midline mucinosis, but atypical areas such as arms, abdomen, face and legs are occasionally involved. The disease have relapsing and remitting course and the disease is limited to skin. Prognosis of this entity is favourable. (4)

The pathogenesis of this entity is unclear, however associations with certain disorders such as haematological malignancies, solid organ malignancies (e.g. breast, lung, colon), thyroid disorders, diabetes, idiopathic thrombocytopenic purpura and systemic lupus erythematosus have been sometimes associated. There is upswing of the disease by menses, oral contraceptives, pregnancy, heat and smoking. Sun exposure can flare or ameliorate the disease course. Viral infections (e.g. HIV) and immunological disturbances have been conjectured to be linked with the induction of REM syndrome.(5)

Within the heterogenous group of cutaneous mucinosis, REM endure clinical and histologic resemblance to LET.(6)

Lupus erythematos tumidus dermal form of lupus erythematosus, which is commonly evident with non scarring, bright red or voilaceous, urticarial plaques with no surface changes such as follicular plugging.(1) They involve face, neck, upper back, extensor aspects of arms, and shoulders. The mean age of onset is fourth or fifth decade with almost equal sex incidence.(7) There are association of LET with SLE and discoid lupus erythmatosus anecdotally reported. It is an extremely photosensitive form of CCLE with negative ANA pattern.(1) Biopsy findings of REM show more superficial inflammatory infiltrate around the adenexa and vessels, but in case of LET the perivascular and perifollicular lymphocytic infiltrate is more dense and is situated deeper the infiltrate is more intense in LET. The mucin deposition in the dermis is more abundant and present in deep dermis in LET, whereas in REM it is present in superficial dermis. (8)

Antimalarials improve the skin lesions of REM patients significantly. They are the first line of treatment for the disease. The lesion generally heal within 1-2 months. Topical calcineurin inhibitors, topical and systemic corticosteroids are the 2nd line treatment. Topical and systemic agents can be combined for better results.(9)

REM should be considered in the differential diagnosis of any erythematous maculopapular or plaque like eruption on the upper chest and upper back. Though it may simulate LET, REM is a distinct entity. Clinicopathologic correlation is pivotal in entertaining the diagnosis of REM, as prognosis is certainly favorable of this entity.

Bibliography

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