Tutorial 12

Topics discussed in this Tutorial

White spots DD

Papular dermatitis childhood DD

Localised hyperpigmentation

Congenital localised hyperpigmentation

Lipoatrophy and Lipodystrophy

Granulomas with scars

Violaceous coloured face DD

Compare pemphigus foliaceous, vulgaris and Pemphigoid

 Differential Diagnosis of White Hypopigmented Spots

This is a difficult differential. Using the SIGN DIP mnemonic, the main Squamous diseases are psoriasis, pityriasis rosea, pityriasis lichenoides and pityriasis Alba. The infective ones are syphilis, pinta and leprosy, granulomatous is sarcoid, neoplastic is halo nevus. Drugs are various hypopigmenting chemicals such as phenols. The immunological inflammatory diseases are lichen sclerosis , morphea, scleroderma, lupus and the Vogt-Koyanagi syndrome. Physical causes are radiodermatitis, and idiopathic guttate hypomelanosis. Remember also Degos syndrome and Albo papuloid epidermolysis bullosa.

The image below is pityriasis alba.

The differential diagnosis of papular dermatitis in childhood includes the Gianotti-Crosti syndrome. Juvenile papular dermatitis, which is like Gianotti-Crosti but there is no liver involvement, lymphadenopathy and there are discreet lichenoid lesions on the hands and forearms. There is also a frictional lichenoid eruption of childhood, which is on the knees and the back of the hands. Caterpillar dermatitis, mites and scabies can all cause a papular dermatitis. This image is of the Gianotti- Crosti syndrome Localised hyperpigmentation. It is difficult to get an encompassing Mnemonic that works! Clinically look out for fixed drug reaction and localised scleroderma or the Pasini Pierini variant of morphoea.  Image The mneumonic we used is DAMN PIG PAPA . D for drugs, A for autoimmune, M for metabolic diseases such as ochronosis and N for neoplastic including metastases and mast cell tumours. P is for post inflammatory, I was infective causes and G was granulomatous diseases. The PAPA is P for parapsoriasis, A for amyloid, P for pigmented purpuric dermatosis and the other A for acanthosis nigricans. The image is of a fixed drug reaction.    Congenital localised hyperpigmentation. If multiple spots it was the Peutz-Jeghers syndrome, urticaria pigmentosa or the leopard syndrome. If it occurred in a patterned form it was incontinentia pigmenti, Albright’s disease and Fanconi’s syndrome. If there were café lait spots it was neurofibromatosis, Albright’s or Gaucher’s syndrome. Naegeli’s syndrome is like incontinentia pigmenti but with no previous inflammation. The image is a case of mastocytosis Localised Lipoatrophy can be annular lipodystrophy or post inflammatory, for example after leprosy, lupus or scleroderma. It can be due to drugs such as insulin and corticosteroids. It can be nevoid. The other drugs that commonly cause Lipo atrophy are the drugs used to treat AIDS. HAART drugs commonly cause this problem. Lipodystrophy presents either as a depression, lipoatrophy , or as an induration of the skin. Lipohypertrophy is due to changes in the subcutaneous tissue. Some of the cases of Lipoatrophy associated with HAART have seen a redistribution of subcutaneous fat with accumulation of fat in abdominal and cervical areas. Some 25% to 50% of patients taking HAART drugs develop some form of Lipo dystrophy. Protease inhibitors reduce fat formation in a dose responsive manner. The most common form of Lipoatrophy probably follows the various types of panniculitis. Remember some of the acquired partial Lipodystrophies can be associated with a reduction in the C3 level and with nephritis. Lipohypertrophy can be due to repeated injections of insulin. Normally we think of insulin causing some degree of Lipoatrophy. It is independent of the type of insulin used. Growth hormone injections have also caused Lipohypertrophy. Rotating injection sites tends to stop the Lipohypertrophy forming. Total fat atrophy can occur in a congenital form when it usually is before the age of two with hepatomegaly, xanthomata, an increase in bone growth and an insulin resistant diabetes. In adults when it occurs there is often acromegaly but no hepatomegaly and they may well show acanthosis nigricans as a measure of some insulin resistance. A degree of fat atrophy commonly occurs in scleroderma and there is the Parry Romberg variant when you get facial hemiatrophy. See Dermnet on Morphoea  Fat atrophy from HAART drugs Lupus Vulgaris It presents as a granuloma with scars. The diffuse edge shows that it is not a neoplastic disorder. On the legs it may look like psoriasis but it has scars. What are the various tuberculids? See Dermnet on Cutaneous TB The image is of lupus vulgaris Compare pemphigus foliaceus, pemphigus vulgaris and pemphigoid. Pemphigus foliaceus is usually in age groups of less than 60. Involves the chest and the face, slow with scaling and crusting and spreads to the upper body, mucous membrane involvement is uncommon. Pemphigus vulgaris is also in the less than 60 age group. The mouth is commonly involved. It is slow to spread. Presents as erosions and crusts and can go anywhere. Mucous membrane involvement is common. Pemphigoid typically is in over 60 year olds. It begins often in the flexures and can be localised to the leg. It evolves much faster than pemphigus. You tend to have intact bullae, which may be haemorrhagic. It is seen particularly on the trunk and limbs and mucous membrane involvement is uncommon. This is pemphigus foliaceous If you have a violaceous hue on the face what do you consider in the differential diagnosis? Answer You should consider dermatomyositis or porphyria variegata. If it is all over the face consider Cushing’s or porphyria. Always watch for lupus erythematosus and porphyria occurring together and watch the pill aggravating porphyria variegata. The Carcinoid syndrome can cause an intermittent violaceous flushing.