Pustules

CLINICAL DIAGNOSTIC MANUAL

Pustules are small, elevated skin lesions that contain pus, a fluid composed of inflammatory cells, bacteria, and other cellular debris. These lesions are often associated with infections or inflammation of hair follicles and can appear anywhere on the body, although they are most common in areas with active sebaceous glands, such as the face, chest, and back. Pustules are a sign of a localized inflammatory response and may be associated with various infectious and non-infectious conditions.

Pathology	Symptoms and Clinical Signs	Suspected Diagnosis	Confirmatory Diagnosis
Acne	Pustules on the face, chest, back, along with comedones and nodules.	Medical history, onset in adolescence or young adulthood.	Physical examination, cultures if secondary infections are suspected.
Folliculitis	Pustules centred on hair follicles, pain or tenderness in the affected skin.	Medical history, physical examination.	Confirmation with pus culture if bacterial infection is suspected.
Pustular psoriasis	Sterile pustules on erythematous skin, especially on hands and feet.	History of previous psoriasis, physical examination.	Skin biopsy, histopathological analysis.
Impetigo	Pustules that rupture leaving yellow crusts. Common in children.	Medical history, rapid onset of lesions in children.	Bacterial culture of the lesions.
Herpes simplex	Painful pustules on lips, genitals, or other areas, preceded by tingling or burning.	Medical history, signs of prior herpes infection.	PCR test or viral culture.
Chickenpox	Itchy pustules along with macules, papules, and vesicles. Common in children.	Medical history, contact with infected individuals.	Clinical diagnosis, PCR for varicella-zoster in doubtful cases.
Syphilis (secondary)	Pustules distributed across the body, along with other systemic signs like fever and lymphadenopathy.	Medical history, history of risky sexual contact.	Serological tests (VDRL, FTA-ABS).
Cutaneous candidiasis	Pustules in moist or intertriginous areas, intense itching.	Medical history, examination of affected areas.	Skin culture or potassium hydroxide (KOH) examination.
Infectious eczema	Pustules on pre-existing eczema lesions, along with signs of local infection (erythema, warmth).	Medical history, presence of prior eczema.	Confirmation with culture of infected lesions.