What are the other Names for this Condition? (Also known as/Synonyms)

• Tropical Anhidrosis

What is Miliaria Profunda? (Definition/Background Information)

• Heat rash is an itchy and slightly uncomfortable rash that occurs typically during hot-humid weather, due to excessive sweating. It is a commonly observed condition in children and adults
• There are three main forms of heat rash (or miliaria), which are termed miliaria crystallina, miliaria rubra, and Miliaria Profunda. Miliaria Profunda is the most severe and rare form of heat rash
• Miliaria Profunda involves the deeper layers of skin (specifically, the dermo-epidermal junction). This form usually occurs after the individual has multiple recurrent episodes of miliaria rubra. The condition is often noted in adult males
• The signs and symptoms of Miliaria Profunda include the presence of numerous firm flesh-colored rashes, commonly in the trunk and extremities. The condition may also be accompanied by slight itchiness and fever
• Miliaria Profunda is generally not a serious condition. It usually goes away without the need for any treatments. In most cases, individuals with the condition have an excellent prognosis

Who gets Miliaria Profunda? (Age and Sex Distribution)

• Miliaria Profunda can affect individuals of all ages, but is more common in adults
• Even though both males and females are affected, a male predominance is noted
• The condition is seen worldwide across all races and ethnic groups

What are the Risk Factors for Miliaria Profunda? (Predisposing Factors)

Miliaria Profunda is a form of heat rash. In general, the risk factors for heat rash may include:

• Repeated onset of miliaria rubra is a specific predisposing factor for Miliaria Profunda
• Continuously lying on one side of the body for a prolonged period, such as observed in those who are bedridden
• Athletes who undertake intense physical activity
• Residing in or traveling to hot and humid climates; living in tropical regions
• Working outdoors in hot and humid conditions, such as farmhands, construction workers, etc.
• People who work in hot-humid (indoor) environments such as mine shafts or certain industries
• Presence of high levels of the bacterium Staphylococcus epidermidis increases one’s risk. S. epidermidis is a bacterium that safely lives on the surface of the skin
• Underdeveloped sweat ducts
• Wearing non-porous synthetic clothing, especially during hot periods
• Frequent skin infections
• Individuals who are overweight or obese are at a higher risk for this condition
• Cancer treatments such as radiotherapy
• It may occur as a side effect of certain medications and may include:
  • Induction chemotherapy
  • Drug-induced hyperhidrosis, or the excessive sweating occurring from using certain medications
  • Stevens-Johnson syndrome
  • Toxic epidermal necrolysis
• Genetic disorders such as Morvan syndrome and pseudohypoaldosteronism type I

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Miliaria Profunda? (Etiology)

• Miliaria Profunda is the most severe form of heat rash that involves the deeper skin layers. Blocked pores that trap sweat under the skin cause heat rash
• Visible signs of inflammation emerge when the trapped sweat leaks into surrounding skin and forms tiny pockets
• Miliaria Profunda may also develop from chronic miliaria rubra

The sweat glands may be blocked due to many factors including:

• Tight restrictive clothing
• Intense physical activity
• Presence of a high amount of the bacterium Staphylococcus epidermidis that produces a sticky substance

It is important to note that heat rash is not an infectious condition, and it cannot be transmitted from one individual to another.

What are the Signs and Symptoms of Miliaria Profunda?

The signs and symptoms of Miliaria Profunda depend on the severity of the condition. Miliaria Profunda occurs in the dermis (middle layer of the skin) and is an uncommon form of heat rash. The condition is characterized by:

• Presence of 1-3 mm sized rashes, mostly in the trunk and extremity
• The presence of firm rashes
• Flesh-colored rashes that may resemble goose bumps
• In some, bigger lumps on skin may be noted
• Slight itchiness
• Increased heart rate
• Lack of sweat
• Fever
• In many cases, this form of heat rash is asymptomatic

How is Miliaria Profunda Diagnosed?

Miliaria Profunda may be easily diagnosed and does not have the requirement for detailed tests and/or invasive exams. A healthcare provider or dermatologist will be able to visibly determine the presence of the condition.

Nevertheless, the following tests and exams may be undertaken, if necessary:

• A complete physical examination and a thorough medical history
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Skin or tissue biopsy: A skin or tissue biopsy is performed and sent to a laboratory for a pathological examination, who examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Cultures of skin biopsies, if necessary
• Blister smears may be undertaken to rule out herpes simplex infection

Note: A skin/tissue biopsy is normally not necessary to diagnose heat rash but may be performed to rule out other causes or similar conditions/infections.

A variety of conditions may exhibit similar signs and symptoms. Hence, a differential diagnosis to eliminate other conditions or infections may be considered, before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Miliaria Profunda?

Miliaria Profunda may clear by itself without any complications. In some rare cases, the potential complications may include:

• Increased sweating (hyperhidrosis) may occur in non-affected body areas
• Secondary bacterial infection of the rash, usually by Staph bacteria
• Heat exhaustion: If left untreated, heat exhaustion can infrequently lead to death

How is Miliaria Profunda Treated?

The goal of treatment for Miliaria Profunda is to cool the body and reduce sweating. Once the body has sufficiently cooled, the skin condition is known to disappear. 

Cooling the body may be achieved by:

• Sitting next to a fan or air conditioner/cooler
• Bathing in cold water
• Stopping any physical activity
• Cold water compresses

Topical creams that may be used for severe cases include:

• Hydrocortisone, a weak steroid, to reduce inflammation
• Anhydrous lanolin, to reduce pore blockage
• Calamine lotion, to reduce itching
• Antibiotics may be prescribed for secondary infections, if any

Over-the-counter ointments (not prescribed by healthcare providers) should be avoided as they may cause blockage of the pores and worsen the condition.

How can Miliaria Profunda be Prevented?

Certain preventive measures for Miliaria Profunda include:

• Regularly changing positions of individuals who are confined to a bed or chair
• Sleeping in a well ventilated area
• Using unscented soaps and detergents
• Wearing light, loose fitting cotton fabrics in humid weather
• Avoiding creams or makeup that block pores
• Treating skin infections promptly and adequately
• Considering weight loss in individuals who are overweight or obese
• Review treatments using medications that cause Heat Rash

What is the Prognosis of Miliaria Profunda? (Outcomes/Resolutions)

• In a vast majority of cases, Miliaria Profunda has an excellent prognosis, as it goes away on its own
• Severe cases may need appropriate treatments using topical applications
• Rarely, some serious cases can result in heat exhaustion that may require urgent medical attention

Additional and Relevant Useful Information for Miliaria Profunda:

Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that can potentially worsen the condition.