Thursday, October 23, 2008

Blistering diseases

If there are Blisters The mnemonic is ICI(Imperial Chemical Industries) Inflammatory including Immunological, Contact dermatitis and Infective.
Inflammatory causes can include drugs but remember Immunological causes in the elderly particularly bullous pemphigoid. Contact dermatitis usually gives smaller vesicles rather than blisters but individual vesicles can join up into blisters. Watch for hair dye allergies around the posterior neck and scalp or consider a plant contact dermatitis if the blisters or vesicles are in a linear streaky distribution on exposed surfaces where the patient has brushed up against an offending bush or tree.
Infective causes of blisters are usually staph toxin in origin and go under the name of bullous impetigo. However if the lesions are in a linear distribution but painful and limited to skin dermatomes then consider Herpes zoster or shingles. The Bullous insect bite reaction occurs on the lower legs usually from sand fly bites and the blister is tense and intact.
Blistering drug eruptions are rare but can be seen with the antiepileptic drugs. They are usually explosive in onset and there may be mucosal involvement. Metabolic disorders rarely give rise to skin blisters but a notable exception is seen in porphyria cutanea tarda PCT. These blisters are usually seen on the backs of the hands or feet in sun exposed areas. The blisters are firm and take time to burst. They surrounding skin is not inflammed. An immunological bullous disease that can look very similar is epidermolysis bullosa acquisita, usually seen at sites of trauma.

A more advanced overview of nearly all possible causes of blisters is shown below. A GP would rarely need to refer to it!

Blisters on the trunk include those on the chest,back and abdomen.  On these areas blisters are usually due to Herpes Zoster(unilateral and painful) bullous staph infection,bullous pemphigoid,plant contact dermatitis and drugs causing toxic epidermal necrolysis. Pemphigus blisters are fragile and soon form crusts and erosions.Rarer immunobullous diseases such as dermatitis herpetiformis and linear IgA disease will cause blisters in these areas. Fixed drug eruption may cause localised blistering.

Management Culture for bacteria and viruses,do a Tzanck smear,do a gram stain and biopsy and immunofluorescence if you consider an immunobullous disease is likely.



Herpes Zoster



Bullous pemphigoid



Plant contact

SIGN DIP MEN Overview of Blisters

S-Squamous Bullous Dariers disease, Bullous Lupus erythematosus


I-Infective Impetigo, Staph scalded skin syndrome, Herpes zoster, Bullous tinea, Parvovirus B19, Staph infected varicella, Bullous orf, Pseudomonas septicemia, Hemorrhagic bullae with Vibrio vulnificus, Mucor infection in immunosupressed, Blistering dactylitis


G-Granulomatous


N-Neoplastic Paraneoplastic pemphigus, Bullous mastocytosis, Paraneoplastic pemphigus


D-Drugs Toxic epidermal necrolysis, Fixed drug eruption, Numerous drugs causing the immunobullous disaeases, Pseudoporphyria, Barbiturate coma,


I-Immunological Plant contact dermatitis, Phytophoto dermatitis, Erythema multiforme, Bullous pemphigoid, Pemphigus, Dermatitis herpetiformis, Linear igA disease, Chronic bullous dermatosis of childhood, Bullous lupus, Mucosal Pemphigoid, Epidermolysis bullosa aquisita, Herpes Gestationis, Lichen sclerosus , Bullous morphea, Bullous necrotising vasculitis,


P-Physical Friction blister, Burns, Insect bite reaction, Bullous scabies, Lymphedema, Puva blisters, Tanning bed Pseudoporphyria, Polymorphous light eruption, Edema blisters of the leg, Sucking blisters in neonates,  Epidermolysis bullosa,



M-Metabolic Porphyria cutanea tarda, Diabetes mellitus, Amyloidosis, Blisters of hemodialysis, Mastocytosis,


E-Endocrine Hypothyroidism,


N-Nutritional Pellagra, Acquired zinc deficiency, Acrodermatitis enteropathica,


Others Pompholyx eczema palms and soles, Congenital syphilis, Kindler syndrome, Neonatal purpura fulminans, Incontinentia pigmenti, Bullous ichthyosiform erythroderma


Hemorrhagic Blisters pemphigus, herpes zoster, leukemia, lichen sclerosus


Erosions Pemphigus, Hailey Hailey, Eczema herpeticum


Sheets of skin Staph scalded skin syndrome,Toxic epidermal necrolysis