Tutorial 15

Topics discussed in this Tutorial

Different types of Pustular Psoriasis

Amyloidosis

Juvenile Xanthogranuloma

Letterer Siwe Disease

Epidermolytic hyperkeratosis

Skin lesions in Thyroid disease

Variants of Discoid Lupus

Pigmented Purpuric Dermatoses

Pachyonychia Congenita

Leprosy

 What are the different types of pustular psoriasis?

Answer

There are the localised and generalised types. The localised include acral psoriasis or palmoplantar pustulosis. There is the Hallopeau variant. There is the juvenile napkin localised pustular psoriasis.
The generalised type includes the Von Zumbusch’s where there is a generalised sheet of pustules, the exanthematous where there are discrete pustular lesions. The Von Zumbusch’s like type may be due to steroid withdrawal.  Images in GSA of pustular psoriasis

Stable plaque psoriasis became pustular after intra articular steroid injection

What is the classification of amyloidosis?

Answer

There is a systemic and several localised variants. The systemic type of amyloidosis tends to localise to the fingers and face whereas the localised types particularly macular amyloid is on the upper back and lichen amyloid is primarily on the lower limbs as a brown papular scaly itchy rash.   Images in GSA        Note that amyloidosis can involve the larynx causing hoarseness and it is a cause of leonine facies.

Juvenile Xanthogranuloma   Image in GSA

These pinkish yellow nodules can occur at an early age. They may be single or multiple but are generally self-limiting. They particularly affect the eyes, the lungs, the liver and spleen. Note an association with neurofibromatosis and watch lymphomatoid papulosis as a differential diagnosis.

Periocular bleeding from capillaries in myeloma associated primary systemic amyloidosis.

Letterer-Siwe Disease

This is an acute histiocytosis usually present at birth presenting with seborrhoeic dermatitis papules and purpura. Often the condition occurs in crops. The purpura is particularly in the small of the back, the trunk and the axillae and babies with this condition may have recurrent infections. The Hand-Schuller-Christian type of histiocytosis occurs in two to five year olds. Occasionally in adults.   It will present with diabetes insipidus, proptosis and bone lesions. They may have chronic otitis media. Image in GSA

The eosinophilic granuloma variant tends to present with bone lesions and genital or perianal lesions.

What is epidermolytic hyperkeratosis?

Answer

This is mainly a histopathological finding with clumped keratohyalin granules and vacuolisation of the stratum spinosum and granulosum. It is a feature of several of the ichthyoses as well as the Vorner type of palmoplantar keratoderma. You can see it sometimes in epidermal nevi, in sporadic papules such as epidermolytic acanthomas and sometimes as a chance finding in normal skin. If you see it in an epidermal nevus the issue is often raised as to whether this is a form of mosaicism or whether bullous ichthyosiform erythroderma, which is a form of epidermolytic hyperkeratosis, may occur in a subsequent pregnancy.  Images in GSA of Epidermolytic hyperkeratosis

Skin Lesions and Hypo and Hyperthyroidism    

The skin is basically cold, dry and there are often dermatitic features particularly asteatotic eczema. There may be telangiectasia of the skin with mucin around the eyes causing swelling, pruritus is common, the fingers often have a doughy feeling and the patient may show carotenemia. The facial lines tend to be flattened because of facial oedema and the hair is often dry, coarse and thinned.

The skin lesions in hyperthyroidism include thyroid acropathy with drum like thickening of the nails and nail bed, the skin is often thin, sweaty, hyperaemic, the nails may show onycholysis and there may be pretibial myxedema.   

What are the major variants of discoid lupus?

Answer

They may be local or general. Lupus profundus occurs particularly on the lower legs. There may be no overlying features of lupus but just dermal atrophy or an area of fat atrophy. There is the angiolupoid variant, hypertrophic lupus erythematosus, and there is lupus pernio or chilblain lupus. These variants may represent about 6% of the total number of discoid lupus cases. Chilblain lupus can affect the nails with subungual hyperkeratoses and it can look red or there may be a bluish colouring of the nail plate and the nail can in fact crumble.

Dermnet on Cutaneous lupus

Tumid discoid lupus

Chilblain lupus of the toes

Pigmented Purpuric Dermatoses               

There are various names attached to this characteristic purpuric eruption on the lower legs and you will often call it a capillaritis because of the very small vessels that are damaged and the low level of that damage. Gravitational purpura is a common cause with associated varicose veins. However the named variants include lichen aureus, which is made up of orange/red macules that are grouped. They are sometimes solitary and there are only a few lesions. Image of lichen aureus

There is Schamberg’s variant, which gives a cayenne pepper type rash on the lower legs. Images in GSA

 The Gougerot-Bloom variant gives lichenoid like lesions, which are symmetrical on the lower legs  Image in GSA and there is the Majocchi variant that occurs in young adults sometimes with central clearing and an annular appearance . 

There is another variant called itchy purpura, which occurs in men on the lower legs with a progressive spread. It is useful to check for cryoglobulins, carbromal sensitivity and check for any abnormal immunoglobulins in the blood. There is also a rare contact purpura to some types of wool giving rise to pigmented purpuric dermatosis. I saw a case once in a foundry worker who wore a special woollen pair of trousers to protect himself from any direct heat damage. A similar rash on the lower legs can also be seen in golfers in the summer who walk the course.

Pigmented purpura or capillaritis

Pachyonychia Congenita

Patients with this condition show large thickened nails, leukoplakia, keratosis pilaris and often a pressure keratoderma on the feet. As an aside if you see grouped milia on the big toe think of dystrophic epidermolysis bullosa. Acral milia after blistering are also seen in PCT and EBA.

Thickened nails in pachyonychia congenita

Leprosy

In lepromatous leprosy you have symmetrical nodules, leg oedema, stuffy nose and the lesions have a diffuse edge. In borderline leprosy you have thickened nerves and in indeterminant leprosy you have macular lesions, pink in white individuals and white in black individuals. In borderline tuberculoid you have a diffuse outer edge but a defined inner edge, some sloping to the outer and lesions can be annular and band like. This is the commonest type of leprosy with anaesthesia, lack of hair and no sweating in the centre of the lesions. In tuberculoid leprosy it is often hyperpigmented with a sharp outer edge sloping to the centre. Note the difference with borderline. Again the lesions are anaesthetic with no hair and no sweating and there are thickened nerves particularly the ulnar and the posterior auricular. It is interesting though that if tuberculoid leprosy is on the face you do not get the lesional anaesthesia.

Images of Lepromatous leprosy in GSA

Images of Tuberculoid leprosy in GSA

Images of Indeterminate Leprosy in GSA

Tutorial 25

Topics discussed in this Tutorial

Leprosy

Alopecia mucinosa

Tertiary Syphilis

Skin lesions in Rheumatoid Arthritis

Folliculitis decalvans

Erythema and pain

DD of Pyogenic granuloma

Mucinoses

Red and Painful Plaques DD

Localised pustular psoriasis

Epidermal nevus syndrome 

Acrocyanosis

Rapidly growing lesion 

Another session on Leprosy

Tuberculoid Leprosy involves macules, papules at the edge, a sharp outer edge fading in the way, the colour may be hypopigmented, purplish or red, no sweating, there is a reduction in sensation, there is no hair. You can have palpable nerves. There are a few lesions only and they are usually asymmetrical.
Borderline tuberculoid in contrast has papules with a central clear area but a sharp inner area and it flattens to the outside. It is symmetrical and there are more patches.
Indeterminate leprosy is macular, pink or white.
Borderline leprosy may have palpable nerves as well as nodules. Borderline lepromatous may have palpable nerves as well as nodules and lepromatous can have nodules, infiltrated plaques and in the late stage white macules.

The image below is of tuberculoid leprosy

Fox Fordyce Disease

It is usually seen in women, post puberty. It involves the axillae. There is itch at first in areas of apocrine glands and subsequent domed papules with pigmentation of the papules.

Fox Fordyce disease

Alopecia Mucinosa

The acute benign variant has erythema scale and acute papules. The chronic variant is more widely distributed with plaques. Mucinous MF variants are  seen as plaques on the head and neck, usually grouped, can be scaly flat areas like psoriasis and usually have patulous follicles, which may secrete a clear material.

Benign alopecia mucinosa

Tertiary Syphilis

It is usually the nodular tuberculoid type, flat and serpiginous and then there is the gummatous type. Differentiate a gumma from pyoderma gangrenosum. A gumma is usually painless and chronic and  pyoderma gangrenosum is painful and acute. Remember that sarcoidosis can be scaly.

Tertiary syphilis 

Tertiary syphilis abdomen

Skin Lesions in Rheumatoid Arthritis

Bywaters lesions involve the nail fold and last a few days. They are also seen in lupus erythematosus. You can get purpura, ulcers, rheumatoid nodules, linear bands, sclerotic changes, pyoderma gangrenosum and the various complications of treatment. There is an acute rash, which is like Stills disease. In males you get a sensory and motor neuropathy.

Folliculitis decalvans involves the scalp and other areas. It is seen in middle-aged women. Slow in men. Usually unilateral.

The Graham Little Syndrome

This is lichen planus of the scalp.

Keratosis Pilaris Atrophicans

This is seen in children and it may involve the eyebrows causing scarring and hair loss.

Folliculitis decalvans

Grouped Micro papules

The diagnosis is keratosis pilaris, lichen spinulosus, lichen scrofulosorum, perforating granuloma annulare, sarcoidosis, lichen nitidus, lichen plano pilaris and follicular mucinosis.

Follicular mucinosis neck

Erythromelalgia

You can have primary or secondary. Secondary is due to polycythemia rubra vera and thrombocythemia.

Erythromelalgia hands

Erythema and Pain

Consider thromboangiitis obliterans, erythromelalgia and atherosclerosis. Night pain in seen in both Burgers syndrome and atherosclerosis. In ischemic pain you may have nerve loss as well with trophic skin changes.

Pretibial Myxoedema

It can present as a plaque with orange.peel like surfaces. It can be diffuse and extend down to the foot and it can be elephantine.

The Differential Diagnosis of Pyogenic Granuloma

There are five malignancies and five hyperplasias. The five malignancies are metastasis, Kaposi’s sarcoma, amelanotic melanoma, BCC and spitz nevi. The five hyperplasias are angio lymphoid hyperplasia, pseudo pyogenic granuloma, atypical fibroxanthoma, pyogenic granuloma with surrounding satellite lesions and inflamed seborrhoeic keratosis. Pseudo pyogenic granulomas are found in patients being treated with Retinoids. They are multiple, small and sessile. Telangiectatic epulis is pyogenic granuloma on the lip. Pyogenic granulomas show little collagen but vascular proliferation and a lot of mucin.

Dermnet on Pyogenic Granuloma

Pyogenic granuloma in pregnancy

The Mucinoses

They are classified as being localised, generalised or syndromal. The localised ones are things such as myxoid cysts, papular mucinosis, pretibial myxoedema, reticular erythematous mucinosis and follicular mucinosis. The generalised ones are lichen myxodermatosis, scleromyxedema, myxoedema and scleredema. There are other diseases such as lupus erythematosus that may form mucin. The syndromes are Hunter’s and Hurler’s syndrome, Morquios in which there is generalised telangiectasia, Leroy’s which is like Hurler’s but no corneal opacities. In the mucinoses look for ivory white nodules or ridges in symmetrical areas between the angles of the scapula and the posterior axillary lines. They may be 1 to 10mm in size, it is usually seen in Hunter’s syndrome, which has cloudy corneas in 90% of cases and is an x linked recessive.

The image below are the sipndled fingers of Scleromyxedema

The Differential diagnosis of Red and Painful Plaques      

Consider erysipelas, erysipeloid, cellulitis, necrotising fasciitis, malignancy and a streptococcal gangrene. In erysipeloid you have a circumscribed dull erythema, it is self-limiting. In necrotising fasciitis you have localised anaesthesia surrounding the area within it. Consider also Sweet’s syndrome, familial Mediterranean fever where the red painful plaques involve the legs. The Vitamin K injection reaction where there is no pain. Consider also lupus and vasculitis. Well’s syndrome or Eosinophilic cellulitis tends to have a greenish plaque or a greenish tinge above the plaque and malignant angioendotheliomatosis have plaque like erysipelas but then they develop into nodules. It particularly involves the face in older people. It can look more bruise like.

The image below is a patch of erysipeloid

Localised Pustular Psoriasis    

It can be circinate as in Reiters. It can be acropustulosis of Hallopeau. You can get an annular erythematous form which looks like erythema annulare centrifugum but it is going to have pustules on the edge. You can get an ordinary psoriatic plaque with pustules. You have the palmar plantar pustulosis, you have napkin pustular psoriasis and you can also have an exanthematous type that may be drug induced but it tends to be more generalised rather than localised.

This image is acrodermatitis continua of Hallopeau

Localised pustular psoriasis feet

Some Other General Points

A malignant blue nevus usually comes from the cellular variety, may be present at birth and it is often flat rather than raised.

A myxoid cyst is usually traumatic around the DIP joint and may involve the nail matrix causing a deformity of the nail plate.

Pigmented basal cell skin cancer has a pearly edge and is well defined. It can be seen in arsenic ingestion, it is usually on the back but also consider it in the basal cell nevus syndrome.

A thrombosed haemangioma looks like a superficial spreading melanoma but remember it has been red before it became thrombosed.

You have a nasal tumour. Consider a myxoma, which may be a fibroma with mucin in it.

Watch also children with dome shaped tumours on the scalp or even over the spine centrally. It can be a central glioma on the scalp with ectopic brain in it, so do not stick a punch into it.

Comparing Nevus Spilus with Capillaritis

In a nevus spilus it is flat with a background café au lait spot with speckled pigmentation. Capillaritis can have some speckled pigmentation but there is no background café au lait spot and there may be some punctate bright red recent haemorrhage.

If you are comparing Bowen’s and a superficial spreading BCC watch for the edge of the BCC. It is a pearly edge and Bowen’s does not have it.

Café au Lait spots

You will see them in neurofibromatosis and Albright’s syndrome. The edges of them are much more irregular in Albright’s.

The Epidermal Nevus Syndrome

Generally the epidermal nevi associated with this are larger. They are seen on the scalp and face. The patient may have had epilepsy or some unilateral ocular syndrome. They sometimes can have underlying bone problems. Nevus sebaceous occurs particularly in the scalp area. It has a yellowish colour and often rounded papules associated with it compared with an epidermal nevus. Basal Cell carcinoma or a forme fruste called trichoblastoma, can develop in these lesions along with syringocystadenoma papilliferum.

This is an extensive Epidermal nevus under the breast.

Extensive sebaceous nevus scalp

Three Diseases with Erythema, Bullae and Hyperkeratosis

Consider bullous epidermolytic hyperkeratosis where there is no pigment. Incontinentia pigmenti where there is no erythema and Conradi’s syndrome where there are no bullae and ichthyosis usually clears in the first year of life.

Ichthyosis hystrix is the porcupine man. Nevus unius lateralis is a linear epidermal nevus on one side of the body following Blaschko’s lines.

The Differential Diagnosis of Acrocyanosis   

Acrocyanosis occurs in a young person. It is symmetrical, may be familial, it is persistent. Erythrocyanosis is typically seen over fat and there may be associated follicular erythema seen in the forearms in infants, the buttocks in young boys and the legs in fat girls and it may also show the Koebner phenomenon. Erythromelalgia is not cyanotic, it is red and other diseases associated with it include polycythemia rubra vera. Secondary erythromelalgia can be seen with system lupus with associated hypertension and diabetes. Rowell’s syndrome is discoid lupus or systemic lupus with perniosis and erythema multiforme. In disseminated intravascular coagulation   you get cyanosis initially. Lupus pernio can give a cyanotic presentation particularly in the nose and the ears. It is a form of sarcoidosis and there may be underlying bone and lung problems.
Chilblain lupus. This can occur years after damage to the peripheries. It may evolve into systemic lupus. Acral ischemia can also give rise to erythermalgia like lesions and peripheral cyanosis.

Dermnet on Heat and Cold

These toes show the features of Chilblain Lupus.

A Rapidly Growing Lesion      

It can be a sarcoma or a secondary tumour or a keratoacanthoma. A neuroma is a painful tumour. A granular cell myoblastoma occurs particularly on the foot or the tongue. It has a very striking pathology with large pale cells with a granular cytoplasm and fibroblasts are squeezed between the cells.

Other Causes of Red Plaques

Sweet’s syndrome where you get erythema and plaques on the hands over the knuckles with arthritis, dermatomyositis erysipeloid and malignant angioendothelioma. The latter has two types. There is a type on the scalp of the elderly and there are young people where it is usually paranasal. Note also rosacea. There is no involvement of the folds in rosacea. The papules are not tender and they are perifollicular compared with acne where the papules are tender and in lupus erythematosus the folds of the face are often involved.

Episodic Facial Flushing

It can be emotional, menopausal, alcohol, pheochromocytoma, Cushing’s disease, rosacea, mastocytosis or drugs. There is also the rare Zolinger Ellison syndrome. Facial flushing can also occur in hyperthyroidism. One sided facial flushing can be due to the Sphenopalatine syndrome with rhinitis. The auricular temporal syndrome with hyperhidrosis and the ciliary syndrome with pain lacrimation and headache.

The image below is a Granular Tumour on the forearm