Dermatology lec

1. The skin in systemic
disease

2. The skin and internal
malignancy
 acne seen with some adrenal tumours
 flushing in the carcinoid syndrome
 jaundice with a bile duct carcinoma
Acanthosis nigricans
 is a velvety thickening and pigmentation of the major
flexures
caused by:
 obesity
 metabolic syndrome (including type 2 diabetes with
insulin resistance)
 Drugs as nicotinic acid used to treat hyperlipidaemia
 the chances are high that a malignant tumour is
present, usually within the abdominal cavity.
Erythema gyratum repens
 looks like the grain on wood

4. The skin and internal
malignancy
Acquired hypertrichosis lanuginosa (‘malignant
down’)
 is an excessive and widespread growth of fine lanugo
hair.
Necrolytic migratory erythema
 is a figurate erythema with a moving crusted edge it
signals the presence of a glucagonsecreting tumour of
the pancreas.
Bazex syndrome
 is a papulosquamous eruption of the fingers and toes,
ears and nose, seen with some tumours of the upper
respiratory tract.
Dermatomyositis, other than in childhood
 About 30% of adult patients have an underlying
malignancy. Pay special attention to the ovaries where
ovarian cancer may lurk undetected.

5. The skin and internal
malignancy
Generalized pruritus
 usually a lymphoma
 Superficial thrombophlebitis.
 the migratory type associated with carcinomas of the
pancreas.
Acquired ichthyosis
 especially lymphomas
Acute febrile neutrophilic dermatosis (Sweet’s
syndrome)
 The classic triad found in association with the red
oedematous plaques consists of fever, a raised
erythrocyte sedimentation rate (ESR) and a raised
blood neutrophil count. The most important internal
association is with myeloproliferative disorders.

7. The skin and internal
malignancy
Paraneoplastic pemphigus
 similar to pemphigus vulgaris but with
extensive and persistent mucosal
ulceration.
 It is associated with myeloproliferative
malignancies as well as underlying
carcinomas.
 Others. Pachydermoperiostosis

8. The skin and diabetes mellitus

9. Necrobiosis lipoidica.
 Less than 3% of diabetics have necrobiosis, but
11–62% of patients with necrobiosis will have
diabetes.
 Non-diabetic necrobiosis patients should be
screened for diabetes as some will have impaired
glucose tolerance or diabetes, and some will
become diabetic later.
 The association is with both type 1 and type 2
diabetes.
 The lesions appear as one or more discoloured
areas on the fronts of the shins
 Early plaques are violaceous but atrophy as the
inflammation goes on and are then shiny, atrophic
and brown–red or slightly yellow.

10. The skin and diabetes
mellitus
 The underlying blood vessels are easily seen through
the atrophic skin and the margin may be erythematous
or violet.
 Minor knocks or biopsy can lead to slow-healing ulcers
Treatment
 No treatment is reliably helpful, the atrophy is
permanent
 the best one can expect from medical treatments is
halting of disease progression.
 A strong topical corticosteroid applied to the edge of an
enlarging lesion may halt its expansion.
 There is little evidence that good control of the diabetes
will help the necrobiosis.

12. The skin and diabetes
mellitus
Granuloma annulare.
 Clinically, the lesions of the common type of granuloma
annulare often lie over the knuckles and are composed
of dermal nodules fused into a rough ring shape
 On the hands the lesions are skin-coloured or slightly
pink; elsewhere a purple colour may be seen.
 histology shows a diagnostic palisading granuloma
 Lesions tend to go away over the course of a year or
two.
 Stubborn ones respond to intralesional triamcinolone
injections.
Diabetic dermopathy
 In about 50% of type 1 diabetics, multiple small (0.5–1
cm in diameter) slightly sunken brownish scars can be
found on the limbs, most obviously over the shins.

14. The skin and diabetes
mellitus
Candidal infections
 Staphylococcal infections
Vitiligo
Eruptive xanthomas
Stiff thick skin (diabetic sclerodactyly or
cheiroarthropathy)
 on the fingers and hands, demonstrated by
the ‘prayer sign’ in which the fingers and
palms cannot be opposed properly
Atherosclerosis with ischaemia or gangrene
of feet.
Neuropathic foot ulcers.

15. The skin in liver disease
Pruritus
 This is related to obstructive jaundice
and may precede it
Pigmentation
 With bile pigments and sometimes
melanin
Spider naevi (These are often multiple in
chronic liver disease
Palmar erythema
White nails
 These associate with hypoalbuminaemia

16. The skin in liver disease
 Lichen planus and
cryoglobulinaemia with hepatitis C
infection.
 Polyarteritis nodosa with hepatitis B
infection.
 Porphyria cutanea tarda .
 Xanthomas With primary biliary
cirrhosis
 Hair loss and generalized asteatotic
eczema may occur in alcoholics with
cirrhosis who have become zinc

18. The skin in renal disease
 Pruritus and a generally dry skin.
 Pigmentation A yellowish sallow
colour and pallor from anaemia.
 Half-and-half nail The proximal half is
white and the distal half is pink or
brownish.
 Perforating disorders Small papules
in which collagen or elastic fibres are
being extruded through the epidermis.
 Pseudoporphyria

19. Malabsorption and
malnutrition

20. Xanthomas
 Deposits of fatty material in the skin and
subcutaneous tissues (xanthomas) may
provide the first clue to important disorders of
lipid metabolism.
 Primary hyperlipidaemias are usually genetic.
 Secondary hyperlipidaemia can be found in a
variety of diseases including diabetes,
primary biliary cirrhosis, the nephrotic
syndrome and hypothyroidism.
 Lipid-regulating drugs (e.g. statins and
fibrates) not only stop xanthomas from
appearing, but they also allow them to
resolve.

21. Xanthomas

25. Generalized pruritus
 Pruritus is a symptom with many causes, but
not a disease in its own right.
Itchy patients fall into two groups:
1. those whose pruritus is caused simply by
surface causes (e.g. eczema, lichen planus
and scabies)
2. those who may or may not have an internal
cause for their itching. These patients
require a
 detailed physical examination, including a
careful search for lymphadenopathy
 Investigations including a full blood count,
iron status, urea and electrolytes, liver
function tests, thyroid function tests and a
chest X-ray

26. Causes
Liver disease
 Itching signals biliary obstruction.
 It is an early symptom of primary biliary cirrhosis.
 Colestyramine may help cholestatic pruritus,
possibly by promoting the elimination of bile
salts.
 Other treatments include naltrexone, rifampicin
and ultraviolet B.
Chronic renal failure
 Ultraviolet B phototherapy, naltrexone or
administration of oral activated charcoal may
help.
Iron deficiency
 Treatment with iron may help the itching.

27. Causes
Polycythaemia
 The itching here is usually triggered by a hot bath; it
has a curious pricking quality and lasts about an hour.
Thyroid disease
 Itching and urticaria may occur in hyperthyroidism.
 The dry skin of hypothyroidism may also be itchy.
Diabetes
Internal malignancy
 The prevalence of itching in Hodgkin’s disease may be
as high as 30%.
 It may be unbearable, yet the skin often looks normal.
 Pruritus may occur long before other manifestations of
the disease.
 Itching is uncommon in carcinomatosis.

28. Causes
Neurological disease
 Paroxysmal pruritus has been recorded in multiple
sclerosis and in neurofibromatosis.
 Brain tumours infiltrating the floor of the fourth ventricle
may cause a fierce persistent itching of the nostrils.
Diffuse scleroderma
 may start as itching associated with increasing
pigmentation and early signs of sclerosis.
 Itching is usually severe
The skin of the elderly may itch because it is too dry, or
because it is being irritated.
Pregnancy
Drugs

29. Treatment
 Therapy is symptomatic and consists of
sedative antihistamines
 skin moisturizers, and the avoidance of
rough clothing, overheating and
vasodilatation, including that brought on
by alcohol.
 Ultraviolet B often helps all kinds of
itching, including the itching associated
with chronic renal and liver disease.
 Local applications include calamine and
mixtures containing small amounts of
menthol or phenol

30. THE END
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