Topics discussed in this Tutorial
Lentiginoses
Ichthyoses
Morphoea
Cysts
Graft versus Host
Hartnup disease
DD of brown papules on the skin
Sweat gland tumours
Sarcoidosis
Perleche angular Cheilitis
Reticulate pigmentation
There are various types of lentiginoses. Centro facial ones are horizontally distributed often inherited as an autosomal dominant and appearing in the first year of life and there may be associated mental retardation, epilepsy and spina bifida. Eruptive lentinginoses appear at puberty or after serious illnesses. They may be telangiectatic at first and many turn into dermal nevi. The LEOPARD syndrome is an acronym where the L stands for lentigines, E for ECG, O for ocular hypertelorism, P for pulmonary stenosis, A for abnormalities to genitalia and R for growth retardation. The D is for deafness.
Lentiginoses can also be seen in the Peutz-Jeghers syndrome, the Cronkite Canada syndrome, urticaria pigmentosa and xeroderma pigmentosum. Patterned lentigines may be a feature of dyskeratosis congenita or incontinentia pigmenti.
The image below is of the Peutz Jager Syndrome.
| Multiple lentigenes in Leopard syndrome |
Ichthyoses
Ichthyoses I find are often difficult, but in essence ichthyosis vulgaris spares the flexures, the palms and soles are involved, the back is worse. X-linked ichthyosis is always in boys, the palms and soles are spared and the face and abdomen are worse and lamellar ichthyosis affects everything and the back is worse.
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| Lamellar ichthyosis |
Morphea
In morphea the pigmentation can precede the onset of the sclerotic plaque. Pigmentation is presumably due to irritation of the junctional melanocytes as part of the inflammatory process which can be quite subtle. The laying down of collagen is a later phenomenon.
Purplish infiltrates are due to mycosis fungoides, leukaemia or granulomas.
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| Acute leukemic infiltrates skin |
The image below is morphea showing the central firm collagen thickening and the peripheral hyperpigmentation.
Cysts
Dermoid cysts are found at the lateral eyelid or eyebrow. Apocrine hidrocystomas are in the same areas. They can be bluish like melanoma or cystic basal cell carcinoma. Eccrine hidrocystomas are on the face and mainly the eyelids. They are smaller than apocrine and may be single or multiple and again have a bluish tinge. Steatocystoma multiplex are multiple, mainly on the upper chest and they have a small punctum maybe associated with comedones.
The image below is an apocrine cyst
Acute graft versus host disease presents with macular erythema. Sometimes unusual areas are involved such as the earlobes, the fingertips and always check the face and neck. If you get sclerodermoid or lichenoid features then it is chronic graft versus host disease.
Diseases in Scars
These can be due to lichen myxedematosis, Leishmaniasis, TB, leprosy, sarcoidosis, even pemphigoid and lupus. Occasionally you will get BCCs or SCCs developing in scars especially old radiotherapy scars or vaccination BCG scars.
Woronof’s Ring
This is due to a deficiency of prostaglandins. It is sometimes seen around lesions of psoriasis. It is an area of pallor around a psoriasis plaque.
The classic features are light sensitivity with pellagra like eruption. They may get cerebellar ataxia. The tongue can be involved as well. The ataxia can be intermittent with associated tryptophan deficiency because there is no nicotinamide synthesis. Typically it presents between three and nine years of age. There may be associated diarrhoea and it may improve with age. Remember Cockaynes syndrome as a differential.
The Differential Diagnosis of Brown Papules
Consider histiocytosis, Darier’s, xanthomas, sarcoidosis, confluent nd reticulated papillomatosis, urticaria pigmentosa, lichen amyloid, syphilis, yaws and leishmaniasis.
Sarcoidosis
In sarcoidosis the annular variant is usually subacute. The micropapular stage on the face and extensor limbs is seen in more acute presentations of sarcoidosis. Lung disease is due to a spirochete Borrelia. It can give rise to arthritis and a sterile meningitis and also acrodermatitis chronica atrophicans.
The image below is sarcoidosis
Eccrine hidrocystomas affect the cheek and eyelids. Apocrine hidrocystomas are lateral to the eyelids and are blue black in colour. Dermoid cysts in infants are lateral to the eyelid. Eccrine poroma affects the soles of the feet. Eccrine hidrocystomas in females are mainly on the labia and eccrine carcinoma is rare often on the face and it very slowly infiltrates. Microcystic adnexal carcinoma is another unusual tumour that may be sweat gland related. It is essentially a benign lesion but it can infiltrate along nerves and tissue planes quite widely. Again mainly seen in females on cheeks or upper lip skin.
Folliculitis
It should be divided into scarring and non-scarring, superficial and deep, infective and non-infective.
The image below is folliculitis in leukaemia
Generalised Pigmentation
In mnemonics DAMNE ANNE with drugs, autoimmune, metabolic, neoplastic and endocrine causes, the ANNE standing for autoimmune, neoplastic, nutritional and endocrine. Addisonian pigmentation is in light exposed areas with flexures and sites of pressure being involved and also the creases, the palms and soles. The mouth is also involved. Interestingly vitiligo like lesions may also occur in Addison’s disease.
Perleche or Angular Cheilitis It can be physical or nutritional particularly with deficiencies of iron, zinc and vitamins, infective from candida, staph and syphilis, vegetating from acanthosis nigricans and pemphigus. It can be seen in other skin diseases such as atopy. Congenital perleche is a feature of Down’s Syndrome and it can also occur with drugs such as Roaccutane. Vegetating Lesions Around the Anus Consider warts, condylomata lata, pemphigus vegetans, acanthosis nigricans, Darier’s disease and histiocytosis X. | |
| Reticulate Pigmentation Amyloidosis is the diagnosis of a macular reticulate pigmentation and itch on the upper back. Dowling Degos disease can occur if it involves the flexures in the neck. The reticulate pigmentation of Naegeli occurs in the second and third year of life involving the neck and axillae and there is often keratoderma of the palms and soles and hypohidrosis.Typically they have yellow teeth. The image below is macular amyloidosis. |








