The skin is the largest human organ, accounting for more than 10% of the bodyâ€™s mass. Multiple functions of the skin include shock absorption, water preservation, and calorie reservation.
The skin is the largest human organ, accounting for more than 10% of the body’s mass. Multiple functions of the skin include shock absorption, water preservation, and calorie reservation. Additionally, the skin synthesizes vitamin D, provides protection, and aids in temperature control.
Alterations in the skin’s integrity are inevitable and frequently result in the development of blisters and sores. A blister is defined as a circumscribed elevated epidermal containing fluid, and a sore can be described as any raw or painful lesion of the body.
Blisters and sores can be attributed to biological, physical, mechanical, or chemical causes.
Parasites, plants, and microorganisms compose a majority of the biological agents. Physical causes include extreme temperatures (hot or cold) and radiation. Friction, pressure, and abrasions account for the mechanical sources. Splashes, immersion, aerosols, or contaminated surfaces cause exposure to chemical agents.
Treatment of all types of blisters and sores is typically based on professional experience.
Initial assessment of blisters and sores should include evaluation of the location, distribution, size, height, and fluctuance. The color of the fluid within a blister or drainage from a sore is also a consideration (clear, cloudy, bloody). General assessment of the patient should also include duration of the blister or sore, and presence of pruritus, sensory neuropathy or pain. Additional history should include the patient’s ability to ambulate and provide self-care, as well as their general health, comorbidities, current medications, and age.
The differential diagnosis for blisters and sores should include the following conditions:
Presentation and Treatment
The presentation and treatment of blisters and sores vary by diagnosis.
Outpatient care of burns should include follow-up assessment and evaluation to ensure successful healing. First-degree burns, like sunburn, involve only the epidermis. Antibiotic ointment or aloe can be used to treat superficial burns. Healing usually is complete in 5 to 10 days.
Second-degree burns involve both the epidermis and dermis. These burns are characterized by clear blisters and weeping, and they are usually painful when touched. Topical antimicrobial agents or an absorptive occlusive dressing is recommended for treating these partial-thickness burns.
4Full-thickness burns may require excision and grafting, so patients should be referred to a specialist for evaluation and management.
Locations of friction blisters are typically palms, soles, fingers, and toes. They can be a reoccurring issue for athletes, runners, skaters, and soldiers. Well-fitted footwear and cushioning socks can reduce friction and prevent friction blisters from forming. Risk of infection is decreased when the blister is left intact, and time is typically the only required treatment. Oral antibiotics can be prescribed if concern for infection development exists.
Abrupt development of bullae in diabetic patients, typically on acral areas, can lead to the diagnosis of bullosis diabeticorum. History-taking must indicate an absence of both systemic symptoms and medication changes. These blisters may appear over 1 to 2 days without additional symptoms. Treatment is unnecessary, as the blisters will resolve over several weeks. Reoccurrences are frequent, and darker pigmentation may remain after the blisters have disappeared.
Red sores, typically found in children, characterize impetigo. Classic presentation of this highly infectious condition appears as sores on the face, hands, and feet. The course of the condition includes the development of honey-colored crusts after the sores burst. Treatment with antibiotic cream and oral antibiotics, if the condition is widespread, is recommended to prevent the spread of the condition to others. Prior to the application of antibiotic cream, warm compresses should be used to remove the scab and allow the medication to penetrate. It is important to educate the patient or parent to avoid contact with others for the first 24 hours of antibiotic treatment to prevent spreading to others.
Most patients experience insect bites and develop a pruritic reddened bump lasting a few days. For others, blistering lesions and hives can occur. Blisters from insect bites should be carefully cleaned with soap and water, while trying to avoid breaking the blister. Topical steroids and oral antihistamines can be used for symptom relief. Patients who experience a severe reaction or anaphylaxis should be evaluated by an allergist or immunologist and should carry injectable epinephrine.
Patient education related to avoiding contact with insects by wearing protective clothing, using insect repellent sprays, and limiting time outside during peak insect activity is beneficial.
A diagnosis of contact dermatitis relies heavily on the patient history, timeline of exposure, and physical examination. Poison oak, poison ivy, and sumac of the Toxicodendron genus is the causative agent in most plant-related contact dermatitis. In addition, the compositae family of plants can also cause a reaction for some patients. These plants include ragweed, goldenrod, sunflowers, and chrysanthemums. These exposures can be from direct physical contact or from airborne particles.
Other causative agents may include dust particles from wood, cement, or metals (nickel, silver, mercury, and gold). Occupational exposures leading to contact dermatitis may include pharmaceutical agents, pesticides, latex, cleaning products, hair dyes, food preservatives, or animal dander.
The American Academy of Allergy, Asthma, and Immunology and the American College of Allergy, Asthma, and Immunology, both, recommend topical steroids for localized minor contact dermatitis. Systemic corticosteroids are best for lesions covering more than 20% of the body’s surface, or if blisters have formed. Oral steroids can be dosed at 1 mg/kg/day and should be tapered over 14 to 21 days. Shorter treatment span may result in a rebound rash.
Weeping lesions benefit from treatment with tepid baths and calamine lotion to promote drying.
The importance of avoiding future exposure to the causative agent and seeking consultation of an allergist or immunologist for recurrent episodes is recommended.
Drug Reactions and Eruptions
Cutaneous reactions are the most commonly reported adverse drug reactions.
Manifestations can range from a mild burning sensation and itching to bullous lesions.
Steven-Johnson syndrome (SJS) is the most severe cutaneous adverse reaction and can be life-threatening. SJS is characterized by diffuse blistering involving the skin and mucous membranes. Widespread skin detachment may develop.
Some of the drugs attributed to cutaneous reactions include nonnarcotic analgesics, antibacterial agents, antifungal agents, antipsychotics, and anticonvulsant agents. Reactions can occur within 1 to 2 days after drug initiation, and up to 3 or 4 weeks after drug initiation. Prior reactions to medications, increased age, and taking multiple medications can increase the likelihood of a cutaneous reaction.
Treatment should include stopping the offending medication, then beginning a tapering dose of oral steroids, topical steroids, and antihistamines.
All blisters and sores should be considered for some risk of infection. Changes in exudate, if present, can signal a need for reassessment. These changes could
include color, amount, viscosity, or smell of the fluid. Also, new or increased pain, localized erythema, or delayed healing should be evaluated further.
presenting with blisters and sores outside of the expected classic findings should be considered for a more extensive evaluation, including lab studies to evaluate
inflammation, culture of any exudate, and possible biopsy of the surrounding tissues.
Uncomplicated blisters and sores typically respond well to treatment and
resolve rather quickly. Removal of the causative agent and following recommended treatments should also prevent reoccurrences.
Updated May 10, 2016. Accessed June 3, 2016.