Differential Diagnosis for Linear Pustules
Single Most Likely Diagnosis
- Koebner phenomenon in psoriasis: This condition is characterized by the appearance of skin lesions on lines of trauma, which could present as linear pustules. The Koebner phenomenon is a well-documented response in psoriasis where skin injury leads to the development of new psoriatic lesions.
Other Likely Diagnoses
- Contact dermatitis: Allergic or irritant contact dermatitis can present with linear or patterned distribution if the causative agent is applied in a linear fashion, potentially leading to pustular lesions.
- Linear IgA disease: An autoimmune condition that can cause blistering or pustular skin eruptions, sometimes in a linear pattern, due to the deposition of IgA antibodies along the basement membrane zone.
- Pustular dermatitis: A condition that can present with pustules and may have a linear distribution if caused by an external agent applied in a linear fashion.
Do Not Miss Diagnoses
- Infectious causes (e.g., impetigo, folliculitis): Bacterial infections can cause pustular lesions and, if not treated, can lead to more serious complications such as cellulitis or abscesses.
- Scabies: Caused by the mite Sarcoptes scabiei, scabies can present with severe itching and pustules, especially in the context of crusted scabies, which can be more difficult to diagnose.
Rare Diagnoses
- Blastomycosis: A fungal infection that can cause skin lesions, including pustules, though it is less common and typically associated with systemic symptoms.
- Linear porokeratosis: A rare genetic disorder characterized by the development of atypical keratinocytes along lines of Blaschko, which can sometimes present with pustular lesions.
- Lichen striatus: A rare, self-limiting condition that affects the skin, often presenting with a linear inflammatory eruption that can include pustules, typically in children.