<unk>  can be classified according to the top level at which obstruction occurs in the sweat glands.<unk>  crystalline The most superficial obstruction (with the most mild clinical presentation), is known as<unk>  crystalline; instead of a rash, the patient presents with multiple, tiny, blister-like lesions that look like beads of perspiration and essentially cause no symptoms.<unk>  crystalline is also known as<unk>  crystallina, and sudamina. The superficial vesicles are not associated with an inflammatory reaction.<unk>  rubra The most commonly encountered form of the illness is<unk>  rubra, in which obstruction causes leakage of sweat into the deeper layers of the epidermis, provoking a local inflammatory reaction and giving rise to the typical appearance of redness (hence rubra) and larger (but still only a few millimetres), blister-like lesions. This form of the illness is often accompanied by the typical symptoms—intense itching or "pins and needles" with a lack of sweating (anhidrosis) to affected areas. A small risk of heat exhaustion exists due to inability to sweat if the rash affects a large proportion of the body's surface area or the sufferer continues to engage in heat-producing activity.<unk>  rubra is also known as prickly heat and heat rash. Differential diagnosis should be used to rule out polycythemia vera, which is a rare hematological disorder and appears more often in males than females, generally not before the age of 40. Both disorders share a common trait of appearing after taking a hot shower.<unk>  profunda The most severe form of<unk> ,<unk>  profunda, sometimes referred to as "wildfire" due to the rapid spread and severe burning sensations, generally occurs as a complication of repeated episodes of<unk>  rubra. The obstruction is deep in the structure of the sweat gland, causing the gland's secretions to leak between the superficial and deep layers of the skin. The rash and associated symptoms tend to appear within hours of an activity provoking sweating, but similarly fade within hours when the stimulus for the sweating is removed.<unk>  profunda is characterised by nonpruritic, flesh-coloured, deep-seated, whitish papules. The rash tends to be flesh-coloured as opposed to the prominent redness of<unk>  rubra, and the risk of heat exhaustion is larger.<unk>  profunda is also less commonly known as "mammillaria"<unk>  pustulosa<unk>  pustulosa describes pustules due to inflammation and bacterial infection.<unk>  pustulosa is preceded by another dermatitis that has produced injury, destruction, or blocking of the sweat ducts. Postmiliarial hypohidrosis Postmiliarial hypohidrosis is a skin condition that results from occlusion of sweat ducts and pores, and may be severe enough to impair an individual's ability to perform sustained work in a hot environment. Tropical anhidrotic asthenia Tropical anhidrotic asthenia is a skin condition, a rare form of<unk> , with long-lasting poral occlusion, which produces anhidrosis and heat retention. Occlusion<unk>  Occlusion<unk>  is a skin condition that is accompanied by anhidrosis and increased heat-stress susceptibility, all after the application of extensive polyethylene film occlusion for 48 hours or longer. Colloid milium Colloid milium is a skin condition characterized by a translucent, flesh-colored, or slightly yellow, 1 to 5 mm papules.
Miliaria
Acne
Sequela
Tinea capitis
Capillaritis
Rosacea 
Rosacea
Ocular rosacea