Here are two diseases that are easy to confuse: pemphigus vulgaris and bullous pemphigoid. Both diseases are characterized by bullae (big, blister-like skin lesions) and both have “pemphig” in their names (“pemphig-” comes from the Greek pemphix, meaning blister, so that makes sense). So what are the differences between the two?
Here’s the key to differentiating between the two disorders. “Pemphigus” is used in a very specific way (you’d think it would be used to describe any blistering disorder, but not so!). It is used to describe blistering disorders caused by autoantibodies against some part of the epidermis, which lead to disruption of the intercellular junctions (and hence bullae). Pemphigus vulgaris, not surprisingly, is the most common type of pemphigus (“vulgar-” comes from the Latin vulgaris, meaning the general public). It occurs primarily in adults between the ages of 30 and 60, and is characterized by big, flaccid bullae that burst easily (in most patients, you’ll see more ruptured, scab-covered bullae than intact ones). Patients often present first with oral bullae and ulcerations, and later develop bullae on the skin.
In this disease, patients have autoantibodies against desmogleins, which disrupt the connections between the squamous cells of the epidermis and cause very superficial, intraepidermal, fragile bullae. If you do immunofluorescence on the skin, you’ll see a kind of outlining of each individual epidermal cell (because there are autoantibodies bound to the junctions between the cells). Treatment consists of immunosuppressive agents; prognosis is variable, but many patients have a higher than normal mortality rate.
This disease is called pemphigoid rather than pemphigus, because it looks like pemphigus but really isn’t! Pemphigus is characterized by autoantibodies against the connections between epidermal cells. In bullous pemphigoid, patients have autoantibodies – but they are against the basement membrane of the epidermis, not against epidermal cell junctions. This means that the bullae are actually subepidermal, so they are less fragile than those of pemphigus vulgaris (if you see a patient with bullous pemphigoid, you’ll see lots of intact, tense bullae, rather than a bunch of ruptured bullae covered with scabs). The immunofluorescence pattern is correspondingly different – you’ll see just a line at the base of the epidermis (rather than the lace-like outlining of epidermal cells you see in pemphigus vulgaris).
Patients with bullous pemphigoid are generally elderly, and the clinical presentation varies a lot (but usually it doesn’t start in the mouth, like pemphigus vulgaris). It’s a less serious disease, usually, since the bullae often don’t rupture (so there’s less chance of infection and scarring).
So if you can remember that pemphigus is a disease that has intraepidermal antibodies, then you can keep the clinical presentation and immunofluorescence pattern of the two diseases straight.
We need your help! Pathology Student is completely ad-free.If you find us useful, please consider donating whatever feels right to you. Every bit helps!You can donate here.
- Kristine said Good question. Auer rods are not seen in chronic phase chronic myeloid leukemia (CML). Rarely, they...
- Krishna said can’t we see Auer rods in CML
- marwa said many thanks
- Charles Piatt, LVT said Thanks so much….good information even for veterinary lab! Love the site!!
- Sepehr said Very helpful , Thanks every1
- jyothsna said Thanks a lot
- jyothsna said Thank u..it was very useful
- ndy said Thanks
- Javed Ali said Greeting!! read the information about DAT test It is realy helpul and easy to understand thanks R...
- Steve Hudson said Thank you so much for your work on the Bites. I print and post in the Lab on pretty much a daily bas...
- sana khanam said nice information
- sana khanam said to make a difficult topic seem so easy to understand is really an art u’v mastered