Diffuse Indurated Skin

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379
Annals Academy of Medicine
Diffuse Indurated Skin
Diffuse Indurated Skin—Vanessa ZY Lim and Hong Liang Tey
Images in Medicine
Answer: B
A healthy 60-year-old Chinese male presented with
a 3-week history of progressive patchy discolouration,
pain and swelling of bilateral lower limbs (left more than
right), associated with constitutional symptoms of appetite
loss. There was no preceding trauma, new drugs or topical
applications. Clinical examination revealed extensive
indurated skin over both lower limbs, extending to the
inguinal fold on the left (Fig. 1). The tightness of the skin
had precluded him from bending his left knee.
Magnetic resonance imaging (MRI) of the left lower limb
showed diffuse skin thickening and a reticular pattern in
the subcutaneous fat, in keeping with skin inammation
(Fig. 2). Blood tests were unremarkable and there was no
paraproteinaemia. A malignancy workup, comprising of
computed tomography (CT) of the thorax, abdomen and
pelvis and endoscopic evaluations, was negative. Histology
of a skin biopsy revealed mucin deposits in the dermis,
thickened collagen bundles and broblastic proliferation.
The skin induration improved with topical application
of 0.1% betamethasone valerate ointment but the patient
subsequently defaulted follow-up.
What is the most likely diagnosis?
A. Systemic sclerosis
B. Scleromyxoedema
C. Nephrogenic systemic brosis
D. Acute lipodermatosclerosis
E. Pretibial myxoedema
Discussion
It is important to differentiate between the various
conditions (such as those in options A to E) presenting
clinically with indurated and hardened skin, in order to
correctly identify associated underlying diseases that may
be life threatening. Scleromyxoedema is the generalised
form of lichen myxoedematosus, an idiopathic cutaneous
disorder characterised by the proliferation of broblasts
with excess mucin deposits in the skin, sparing the
mucous membranes. The generalised form may involve
internal organs and can be fatal. It is often associated
with monoclonal gammopathy, or other bone marrow
malignancies,1 although not in this case.
Fig. 1. Extensive indurated skin extending to the inguinal fold on the left
lower limb.
Fig. 2. Magnetic resonance imaging (MRI) images of diffuse skin thickening
and a reticular pattern seen in the subcutaneous fat extending from the level
of the upper thigh to the ankle.

August 2016, Vol. 45 No. 8
380
Diffuse Indurated Skin—Vanessa ZY Lim and Hong Liang Tey
The skin induration may resemble scleroderma of
systemic sclerosis, but the latter is characterised by an
excess production of collagen in the dermis, rather than
mucin. There is no associated calcinosis or telangiectasia
in scleromyxoedema.1 Nephrogenic systemic brosis has
almost identical histology features with scleromyxoedema,
with excess mucin production and broblast proliferation,
but occurs in patients with renal failure and may be
precipitated by the use of gadolinium-containing contrast
agents.1
Lipodermatosclerosis is a type of panniculitis that
typically affects patients with venous insufciency. In
the acute inammatory state, patients often present with
swelling, skin induration and hyperpigmentation over
their lower limbs, with histology revealing a lymphocytic
inltrate and tissue necrosis in the subcutaneous fat layer.2
In pretibial myxoedema, the areas affected are localised to
the anterior-lateral shins, and is almost always associated
with Grave’s disease.3 The histological ndings of pretibial
myxoedema include increased mucin production and
stellate-shaped broblasts, but there is no increase in the
number of broblasts.3
Another much rarer condition that also causes diffuse
indurated skin is scleredema, but it typically affects the
upper body, and is associated with a history of a prior upper
respiratory tract streptococcal infection, diabetes mellitus
or monoclonal gammopathy. Histologically, scleredema is
due to an excess production of both collagen and mucin
in the dermis; the absence of broblast proliferation
differentiates it from scleromyxoedema.1
Management of scleromyxoedema includes the
evaluation of internal organ involvement and underlying
malignancies. Various therapies have been tried to varying
success, such as intravenous immunoglobulin, thalidomide
and corticosteroids.1
Conclusion
Diseases resulting in hardening of the skin are
characterised by an increase in collagen production, mucin
production, and/or the number of broblasts in the dermis.
These require to be differentiated, as there can be different
associated systemic involvements and malignancies, and
therefore varying treatment options and prognoses.
Vanessa ZY Lim, 1MBBS, MRCP (UK), Hong Liang Tey, 1,2MBBS,
FRCP (Edin), FAMS
1National Skin Centre, Singapore
2Lee Kong Chian School of Medicine, Singapore
Address for Correspondence: Dr Tey Hong Liang, National Skin Centre, 1
Mandalay Road, Singapore 308205.
Email: teyhongliang111@yahoo.com
REFERENCES
1. Boin F, Hummers LK. Scleroderma-like brosing disorders. Rheum Dis
Clin North Am 2008;34:199-220.
2. Kirsner RS, Pardes JB, Eaglestein WH, Falanga V. The clinical spectrum
of lipodermatosclerosis. J Am Acad Dermatol 1993;28:623-7.
3. Holahan HM, Farah RS, Swick BL. Pretibial myxedema. Cutis
2014;94:60,73-4.