52
VOLUME 10 NUMBER 2 • JUNE 2013
REVIEW
SA JOURNAL OF DIABETES & VASCULAR DISEASE
Necrobiosis lipoidica
Necrobiosis lipoidica (NL) is an uncommon condition with only 0.3-
1.6% of patients with DM developing NL (Figs 1, 2). However, more
than 66% of patients with NL have diabetes and therefore it should
be regarded as a cutaneous marker of DM until proven otherwise.
NL has other associations as well and these include sarcoidosis,
rheumatoid arthritis, inflammatory bowel disease and adult-onset
Still’s disease.
Diabetic dermopathy
Diabetic dermopathy is also known as ‘shin spots’ and pigmented
pretibial papules. This is the most common skin lesion occurring in
DM, although not specific for DM as 20%of healthy individuals may
have similar lesions. Prevalence in patients with DM varies from 7%
to 70%. Men are affected more often than women. This condition
is important as it may precede abnormal glucose metabolism.
Although commonly presenting on the extensor aspects of the
lower limbs, they may rarely occur elsewhere as well. The clinician
usually sees only the end result of atrophic and hyperpigmented
plaques. The active lesions tend to be red and polycyclic. Treatment
is not effective and some lesions resolve spontaneously.
Eruptive xanthomas
Eruptive xanthomas (Fig. 3) present as small (1-2mm) yellowpapules,
often with erythematous borders. Their development is associated
with elevated levels of triglyceride-rich lipoproteins and they tend
to resolve rapidly with control of the metabolic disturbance.
NL classically presents as a non-scaling plaque with an atrophic
yellow centre, which may ulcerate in 35% of cases, and a red
elevated border. The pretibial region is the area typically affected,
but it may occur elsewhere as well. Women are affected more often
than men and those with type 1 DM tend to develop NL earlier than
type 2 DM. Metabolic control has no proven effect on the course of
this condition. NL is very resistant to treatment and options include
application of a topical steroid with or without occlusion; and
intralesional steroids into the active border.
Figure 1.
Necrobiosis lipoidica – early stage.
NL starts as a non-scaling red papule and spreads centrifugally, with the yellow
discoloration and atrophy developing centrally. The yellow colour follows as a
consequence of the underlying fibrosis in the dermis.
Figure 2.
Necrobiosis lipoidica – advanced stage.
A large plaque of NL clearly demonstrating atrophy in the centre with a promi-
nent red border.
Figure 3.
Eruptive xanthomas.
Note the multiple red papules and nodules with a yellowish hue on the extensor
surfaces of the forearms. The yellow hue is due to foamy macrophages contain-
ing lipid found in the infiltrate.
Diabetic cheiroarthropathy
Diabetic cheiroarthropathy, also known as diabetic stiff hand
syndrome or limited joint mobility syndrome, is characterized by
thickened waxy skin and limited joint mobility of the hands and
fingers, leading to flexion contractures. Patients are unable to press
their palms together completely. A gap remains between opposed
palms and fingers. This is called the ‘prayer sign’. Patients may also
present with multiple minute papules, grouped on the extensor side
of the fingers, on the knuckles, or on the periungual surface; known
as pebbled knuckles or Huntley papules. Dupuytren’s contracture
may further complicate diabetic hand syndrome. Diabetic cheiro-
arthropathy is observed in about 30% of DM patients with long-
standing disease and prevalence increases with the duration of
diabetes. This condition is predictive of other diabetic complications.
The pathogenesis includes increased glycosylation of collagen in the
skin and periarticular tissue, decreased collagen degradation, diabetic
microangiopathy and possibly diabetic neuropathy. Unfortunately,
this is not a treatable condition.
