Topics covered in this Tutorial
Vasculitis
Bullae
Herpes Gestationis
Hemorrhagic Bullae
Pemphigus and Pemphigoid
Flexural rashes
Drug Induced Necrosis
Impetigo
Bullous disease in Neonate
Orf
Vasculitis
Vasculitis can sometimes be classified on the basis of the morphology of the lesions and those with other systems involved. Those causing plaques include leukocytoclastic vasculitis, granuloma faciale, erythema elevatum diutinum, Sweet’s syndrome and systemic lupus.
Those with nodules are nodular cutaneous vasculitis, erythrocyanosis, erythema induratum, erythema nodosum, erythema nodosum migrans and cutaneous polyarteritis nodosa, (sometimes the latter is referred to as livedo with nodules), plus polyarteritis nodosa.
Sometimes vasculitis presents as ulcers and there can be livedo with ulcers, leukocytoclastic vasculitis, lymphomatoid papulosis, Calciphylaxis, lymphomatoid granulomatosis, papulo necrotic tuberculid and midline granuloma and Wegener’s.
Sometimes vasculitis can be subdivided into those with other systems involved, for example hypersensitivity angiitis, Henoch-Schoenlein, polyarteritis nodosa and syndromes such as Sjogren’s.
The image below is vasculitis Henoch Schonlein type
Bullae
Note that if there is little in the way of surrounding reactions, this suggests toxic epidermal necrolysis, pompholyx, pemphigus, epidermolysis bullosa, diabetes and insect bites.
If you have an umbilicated bulla like lesion consider orf. Images in GSA
If you have bullae and non red papules consider urticaria pigmentosa, PCT, lichen sclerosis and incontinentia pigmenti.
If you have erythematous papules and plaques with a blister superimposed on it, in an acute situation consider erythema multiforme but in a chronic situation consider pemphigoid, especially in an older person. Also Linear IgA disease and Chronic bullous disease of childhood. Image in GSA
Bullous morphea occurs very rarely only really when lymphatics are strangulated.
Other Blistering Facts
In toxic epidermal necrolysis, the normal surrounding skin is tender. In dermatitis herpetiformis the skin is itchy and non tender. In pemphigus and pemphigoid the lesions themselves are tender. In pemphigus foliaceous you find that it is symmetrical with a slow build up and the face is scaly. In pemphigoid it is generalised after weeks of being localised and in pemphigus it takes months before it becomes generalised.
In erythema multiforme there are three types, those with papules, those with vesicles and those with blisters. Note it is usually on the face and hands. In bullous impetigo you generally have a positive culture and even when it generalises you have a positive culture but in the generalised staph scalded skin syndrome you often have few bullae and it may not be positive on culture.
The image below is skin sheeting in Toxic epidermal necrolysis.
In herpes gestationis, better named as pemphigoid gestationis, there are often firm blisters with a ring of pearls distribution similar to linear IgA disease. This can be compared with erythema multiforme in which the blister is in the middle of the red areas. In Snedden Wilkinson syndrome the blisters will sometimes show a hypopyon where there is a fluid level in the blister. Necrolytic migratory erythema will have pustules in the advancing edge but it tends to leave pigmentation and in pustular psoriasis the pustules are often thick walled. They are quite deep.
Other Comments
Pemphigus erythematosus gives pigmentation plus bullae plus scarring. See Image In erysipelas you can occasionally get bullae at the advancing edge. Watch for bullae associated with necrotising fasciitis. Image
Haemorrhagic Bullae
This can be a feature of pyoderma gangrenosum, disseminated intravascular coagulation and ecthyma gangrenosum due to pseudomonas, vasculitis and pemphigoid and EBA. Occasionally you will get bleeding into PCT blisters. Image
The image below is pemphigoid gestationis.
Pemphigus and Pemphigoid
Note than when comparing blisters in pemphigus they spread, they are painful and they bleed easily. This is not the case in pemphigoid where they are much more fixed and less likely to form erosions. In pemphigoid there are few lesions on the face. Pemphigus vulgaris and foliaceous often have facial lesions.
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| Pemphigus foliaceous looking like a severe Seb derm |
Light Eruptions
Juvenile Spring eruption is seen in males on the ears and is non-scarring. Hydroa vacciniforme is in males on the face and there is scarring. Hydroa aestivale is in females in non-exposed areas which is unusual for a light eruption and polymorphous light eruption is polymorphic on sun exposed areas and comes out some hours after exposure and is non-scarring.
The image below is the crusting seen in Pemphigus foliaceus
Some Flexural Rashes
In subcorneal pustular dermatosis it occurs in waves with a trailing serpiginous scaly edge. In necrolytic migratory erythema you may have pustules on the edge but there is residual pigmentation. In Hailey-Hailey disease you have fissuring as also in Darier's and pustular psoriasis is very painful. You may get candidiasis with staph like pustules in immunosuppressed patients. Bullous impetigo can give central healing but with activity in the peripheral edges. Remember in pemphigus you get spreading of erosions.
Lesions are much more fixed in pemphigoid. Early pemphigoid often presents as urticarial plaques. Dermatitis herpetiformis often gives larger bullae on the extensor surfaces whereas pemphigoid tends to involve flexural areas.
The image below is of the submammary fissuring seen in Hailey Hailey disease.
Drug Induced Necrosis
Heparin, Warfarin, Dequalinum and cytotoxics.
The Causes of Gangrene
Gangrene of the skin can be due to haematogenous factors, vessel wall damage, vasospasticity, external physical agents, severe infections or abnormal tissue response to infections or other stimuli. Necrosis and levido is typical of calciphylaxis in renal failure patients.
The image below is of Warfarin Necrosis
Lymphadenopathy and Erythema
In this circumstance think of erythema multiforme, Kawasaki’s syndrome, infectious mononucleosis, scarlatina, syphilis and the AIDS conversion syndrome.
The image below is of Kawasaki's disease.
The Tillbury Fox type is a macule that becomes a crusted lesion and it is often a mixed staph and strep infection. Bullous impetigo is essentially a staph infection with an erosion and scale. The blisters rupture easily because they are subcorneal. It is often not crusted. The scale is around the periphery of the lesion. There are three types. It may be generalised in neonates and those who are immunocompromised. There is a type with erythema all over and there is the TENS type similar to the staph scalded skin syndrome.
The image below is of bullous impetigo merging into Staph scaled Skin
Bullous Disease in the Neonate
The common causes are epidermolysis bullosa, bullous impetigo, incontinentia pigmenti, bullous ichthyosiform erythroderma, neonatal pustular melanosis, transient neonatal erythema, urticaria pigmentosa and scabies.
The image below is of the damage caused by recessive epidermolysis bullosa.
Note that in orf the lesion itself is haemorrhagic and not the base of the lesion. This is often reflected in the papillary oedema and the extravasated red blood cells in the histopathology.
The image below is of Orf on the forearm of a Vet.
