What does bullous mean?
Bullous is a medical adjective describing anything characterized by, relating to, or resembling bullae — the large, fluid-filled blisters that can form on the skin or mucous membranes. It derives from the Latin word 'bulla,' which originally meant a bubble or a rounded seal, giving the term both its literal blister-related sense and a more figurative meaning of something bubble- or bleb-like in form. In modern usage, bullous appears overwhelmingly in dermatology and pathology, where it names a family of conditions such as bullous pemphigoid, bullous impetigo, and various bullous dermatoses. Because it is a specialist term, it carries a clinical register: a general reader would say 'blistering,' while a physician writes 'bullous.' The word is easy to confuse visually with 'bulbous,' which describes a rounded, bulb-like swelling rather than a blister. Knowing bullous is useful for anyone reading medical reports, dermatology literature, or patient information about autoimmune skin disease.
adjectiveRelating to, resembling, or characterized by bullae — large fluid-filled blisters on the skin or mucous membranes.
- Of or relating to bullae (large blisters) on the skin or mucous membranes; characterized by the formation of such blisters.
- Resembling or having the form of a bulla; bleb-like.
"The dermatologist diagnosed a bullous eruption on the patient's forearms and prescribed corticosteroids."
"Bullous pemphigoid is an autoimmune condition that causes large, tense blisters to form on the skin."
"On examination, the surgeon noted a bullous lesion along the patient's inner cheek."
Bullous sounds like it should describe something bulb-shaped, but doctors use it for blisters — one letter separates 'swollen' from 'blistered.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bullous
Bullous comes from the Latin 'bulla,' meaning a bubble, knob, or rounded stud, combined with the adjectival suffix '-ous.' In ancient Rome, a bulla was also the name of a locket-like amulet worn by boys, named for its round shape. English adopted the word via New Latin medical terminology, where 'bulla' came to denote a large blister, and 'bullous' emerged as the corresponding adjective in clinical descriptions of blistering skin disease. It shares this Latin root with 'bullate' (puckered or blistered, as some leaves are) and, more distantly, with words like 'bubble' through related Germanic borrowings.
Related word forms
How bullous is actually used
Primarily used in medical and dermatological contexts; rarely encountered outside clinical writing. Considered technical rather than formal — lay readers are more likely to see 'blistering' than 'bullous.' Frequently appears in the names of specific diseases (e.g., bullous pemphigoid).
Easily confused with bullous
Bulbous means swollen like a bulb or rounded in shape, while bullous specifically refers to blisters or blister-like lesions.