Tutorial 11

 

Question 1: Topics discussed in this Tutorial Stages of lesions Spitz nevi in children Red areas on the scrotum The DD of Pyogenic granulomas 5 types of Solar keratoses Dermatomyositis Pretibial myxedema Ichthyosis linearis circumflexa Lichen myxedematosus Lichen nitidus I thought I would follow up on the stages of lesions.  Bullous pemphigoid will present in its earliest phase as an urticaria like rash often with a polycyclic erythema before the more typical thick walled bullae of bullous pemphigoid arise. Image  Early discoid lupus on the face often has no scarring and may present just as a plaque. It can look very like granuloma faciale although if you have multiple lesions then lupus is more likely.  Image  The early lesions of erythema multiforme can be urticarial like and sometimes just have a macular erythema before the more typical target lesions or bullae may occur.  Early erythema nodosum on the shins can present simply as localised erythema. It is interesting though that it is usually painful. This will subsequently be followed by the more obvious subcutaneous nodules and as they resolve the typical bruise like lesion.  When Kaposi’s sarcoma presents on the skin it may present as a macular erythema but note that it will have sharp irregular edges. It is these sharp edges that make it likely to be a tumour. You subsequently have the later darker and then the nodular stage. Spitz nevi in children are often a pink colour. There is no melanin in these lesions, which are rapidly growing. They can look either yellow or red. When yellow the differential diagnosis is xanthogranuloma. Generally spitz nevi in adults have more melanin in them.   Image of agminate Spitz Morphea goes through a variety of stages. Early on there is just a fairly deep erythema then the white centre may develop in the plaque and the skin becomes bound down and when it subsequently resolves you may have an atrophic Pasini and Pierini type.. Herpes simplex around the buttock. You will see this in immunosuppressed patients. Often the edge of the ulcer is very scalloped and this can be a give away for this diagnosis. Image Differentials for this condition can be pyoderma gangrenosum   or bacterial synergistic gangrene. On a leg if a patient has a patch of necrobiosis lipoidica and they have some surrounding bullae especially if they are haemorrhagic the bullae are likely to be diabetic bullae. Multiple erythematous areas on the scrotum, the glans and the shaft of the penis, one should consider psoriasis, Reiter’s disease or extramammary Paget’s. Extramammary Paget’s is usually an intraepidermal adenocarcinoma distant from the site of origin. However around the anus it may be continuous with a rectal carcinoma. Bullous pemphigoid Differential diagnosis of a pyogenic granuloma.  (Lobular capillary hemangioma) Pyogenic granulomas usually bleed very easily. The bandaid sign was first applied to it. Dermatoscopically you have white lines separating the vascular elements. 1.        Kaposi sarcoma. 2.        A melanoma usually amelanotic. 3.        Angio lymphoid hyperplasia.  Red nodules or papules around the ear 4.        Pseudo pyogenic granuloma. This is another name for angiolymphoid hyperplasia! Often found around the auditory meatus. 5. Bacillary angiomatosis - multiple PG like lesions in an HIV patient 6. Others - glomus tumours and Renal cell carcinoma mets. Note increased incidence of PGs with retinoids, MEK 1/2 inhibitors and EGFR inhibitors Pyogenic granuloma When is psoriasis not like psoriasis? And the answer is when it is early or when it is superimposed and been eczematised especially on the lower legs or when it involves the palms and soles, when it can be spongiotic like pompholyx or in flexures where it gives an intertrigo appearance. Eczematised Psoriasis What are the five stages of development of solar keratoses? Answer They can be macular, hyperkeratotic, acantholytic, lichenoid and atrophic. They can also be superficial pigmented. Note also that a reticulated seborrhoeic keratosis often develops from a senile lentigo. See Dermnet on Solar keratoses Dermatomyositis Watch for oedema on the back of the hands and sometimes on the face especially around the eyes. Question What are the other skin features of dermatomyositis? Answer The four main skin features of dermatomyositis are erythema over anterior and posterior upper chest (shawl sign),erythema elbows and knees, Photo rashes, poikiloderma, the facial and nail changes. Pay particular attention to the distribution of the erythema over the joints of the hands and Gottron's papules and the ragged cuticles. Watch for late poikiloderma and calcification in children. There is also a rare violaceous follicular erythema. If a patient with dermatomyositis becomes pregnant 50% foetal mortality can occur. See Dermnet on Dermatomyositis Periorbital oedema Dermatomyositis What are the types of pre tibial myxedema? Answer They are circumscribed, diffuse, non-pitting and elephantiasis. This condition is initially seen in patients who suffer from Graves disease and may also have the typical prominent eyes and thyroid acropachy of the nails. See Dermnet on PreTibial Myxedema Pre Tibial Myxedema What is ichthyosis linearis circumflexa? It shows a circinate raised erythematous band on the trunk with a distinctive double edged scale. It is seen in Netherton syndrome with its ichthyosiform skin changes,trichorrhexis invaginata and atopic dermatitis. Children often have elevated IgE levels. Ichthyosis linearis circumflexa Lichen Myxedematosus Question What are the four clinical sub types of lichen myxedematosus? Answer The generalised lichenoid papular eruption associated with an IgG dermopathy. This is known as scleromyxedema. Secondly there is a papular form affecting the proximal extremities and the trunk. Thirdly there are lichenoid plaques resembling generalised lichen planus and fourthly urticarial nodules and plaques that may progress to the lichenoid form. Lichen myxedematosus is mainly on the upper limbs compared with lichen amyloid, which is mainly on the lower limbs. Question What investigation should be done in the case of lichen myxedematosus? Answer Protein electrophoresis, examination of the urine for Bence Jones protein. Check for chronic hepatitis C. Lichen myxedematosus may progress over time to scleromyxedema, which presents acrally with lesions on the hands that are very similar to scleroderma. Question What drug therapies may be used in lichen myxedematosus? Answer Melphalan has been used but people can develop haematological malignancies when they are on it and also sepsis from immunosuppression.   Though steroids have been helpful in some patients, as has Isotretinoin. Some cases have also been treated with PUVA. See Dermnet on these topics Lichen myxedematosus Lichen Nitidus Presentation is with multiple grouped 1mm to 2mm diameter flat top to domed papules. They generally do not coalesce but remain discreet. They can occur in any parts of the body but primarily affect the forearms, penis, abdomen, chest and buttocks. Rarely palmar lesions can be haemorrhagic. Treatment Some cases have responded to fluorinated topical steroids and antihistamines have been reported to have cleared lesions. PUVA has been used in generalised cases and rarely Acitretin. See Dermnet for pathology of Lichen Nitidus Lichen nitidus